Summit Success Rates by Peak 2026: Real Statistics from K2 to Kilimanjaro — What Actually Drives Whether You Make the Top
Most guidebooks quote a single number — “Aconcagua has a 40 percent success rate” — without context. Generally, that figure means very different things in practice. The answer depends on when you go, which route you take, whether you are guided, and what altitude experience you bring. Specifically, this page disaggregates the data for 24 major peaks so you can see what actually drives outcomes. Notably, real statistics aggregated from park authority reports, guiding company disclosures, and the Himalayan Database — so you can plan around facts, not folklore.
The phrase “summit success rate” sounds like a single number. Generally, it isn’t. Specifically, a peak’s published success rate is a weighted average of many subcategories. The mix includes guided vs independent, Normal Route vs technical, January vs February, and first-time altitude climbers vs experienced veterans. Notably, when those subcategories disaggregate, the apparent precision collapses. A 39 percent success rate on Aconcagua means very different things depending on which subcategory describes you.
This page gives you both the master ranking and the disaggregated view. The master table at top compares all 24 peaks with primary success rate data. Below, four sections cover the variables under your control as a climber. Each peak with its own detailed page links to the dedicated success-rate deep dive.
How to read these numbers. Success is defined as reaching the actual summit. Generally, turnaround decisions include weather holds, illness, voluntary retreats, and operator-mandated turnarounds. Specifically, rescue incidents are tracked separately from failed-summit attempts. Notably, all rates here are computed from climbers who obtained a legal permit. In some cases, the data comes from operator-published statistics on their own clients — which we mark clearly. Operator-reported rates can run 10-20 percentage points higher than park-wide rates due to the self-selected, better-prepared client base.
The Master Comparison: All 24 Peaks Ranked
Below is the master comparison table. Generally, peaks are ranked from highest success rate to lowest. Specifically, the colour-coded left borders match the four difficulty tiers below. Green marks the high-success tier (60 percent+), blue the mid-tier (40-60 percent), orange the low-tier (20-40 percent), and red the extreme tier (under 20 percent). Notably, the spread tracks not just technical difficulty but also commercial guiding intensity, route choices, weather window reliability, and self-selection of climber experience levels.
| Peak | Elevation | Country | Success Rate | Notes |
|---|---|---|---|---|
| Vinson Massif | 4,892m | Antarctica | ~95% | Self-selected experienced base, ALE logistics monopoly, short technical climb once you arrive |
| Island Peak | 6,189m | Nepal | ~80% | The Nepal trekking-peak gateway; commercial infrastructure heavy |
| Mount Elbrus | 5,642m | Russia | ~72% | Cable car to 3,800m, snowcat option, established Russian operator chain |
| Mount Kilimanjaro | 5,895m | Tanzania | ~65% | KPAP-member operators, 8-day Lemosho route runs ~85% |
| Mera Peak | 6,476m | Nepal | ~65% | Highest trekking peak in Nepal; standard 18-day itinerary |
| Carstensz Pyramid | 4,884m | Indonesia | ~60% | Helicopter approach standard 2026; rock climbing technical |
| Mont Blanc | 4,808m | France/Italy | ~58% | IFMGA-guided cohort, Goûter Route standard, weather-dependent |
| Mount Rainier | 4,392m | Washington, USA | ~54% | NPS concessionaire system, Disappointment Cleaver standard route |
| Denali | 6,190m | Alaska, USA | ~51% | West Buttress; cold-weather glacier expedition; 22-day standard |
| Pico de Orizaba | 5,636m | Mexico | ~48% | Glaciated stratovolcano; weather and route conditions variable |
| Mount Shasta | 4,322m | California, USA | ~47% | Avalanche Gulch standard; high seasonal weather variance |
| Chimborazo | 6,263m | Ecuador | ~45% | Highest peak on Earth from centre; weather and ice conditions variable |
| Aconcagua | 6,961m | Argentina | ~39% | Normal Route 47%, guided 51%, independent 29%; Viento Blanco a major factor |
| Cho Oyu | 8,188m | Tibet | ~35% | Lowest-fatality 8000er; Chinese permitting intermittent |
| Manaslu | 8,163m | Nepal | ~33% | Cho Oyu substitute; autumn crowding; avalanche-exposed |
| Lhotse | 8,516m | Nepal/Tibet | ~32% | Often climbed paired with Everest; same lower route |
| Mount Everest | 8,849m | Nepal/Tibet | ~29% | Heavily commercial; premium ops run 65%+; cohort heterogeneous |
| Matterhorn | 4,478m | Switzerland/Italy | ~28% | Hörnli Ridge standard; weather and technical difficulty drive lower rate |
| Dhaulagiri I | 8,167m | Nepal | ~23% | Tier II 8000er; Northeast Ridge standard |
| Makalu | 8,485m | Nepal/Tibet | ~22% | Tier II 8000er; Northwest Ridge sustained steep |
| Kangchenjunga | 8,586m | Nepal/India | ~20% | 3rd highest; remote, long approach, weather-exposed |
| Annapurna I | 8,091m | Nepal | ~17% | Deadliest 8000er; avalanche-driven; Tier I Killer Peak |
| Nanga Parbat | 8,126m | Pakistan | ~16% | Tier I Killer Peak; avalanche, security risks |
| K2 | 8,611m | Pakistan/China | ~14% | Lowest commercially-attempted success rate; Bottleneck serac risk |
The most striking signal in this table. Success rates span almost a 7x range — from Vinson’s roughly 95 percent to K2’s roughly 14 percent. Generally, that spread is not just about technical difficulty. Specifically, Vinson is technically much easier than Aconcagua but has a much higher success rate. The reason is climber self-selection: only experienced, well-funded climbers reach Vinson at all, while Aconcagua attracts altitude novices. Notably, Kilimanjaro and Matterhorn are similar in elevation (5,895m vs 4,478m). But Matterhorn’s success rate (28 percent) is less than half of Kilimanjaro’s (65 percent). The reason: Matterhorn is a technical alpine climb and Kilimanjaro is a high-altitude hike. The single biggest predictor of summit success is not the mountain’s altitude — it’s the match between the climber’s experience and the mountain’s demands.
The Four Drivers of Summit Success
Across every major peak in the dataset, four variables explain the majority of the gap between climbers who summit and climbers who don’t. Generally, all four are under climber control. Specifically, getting them right doubles the typical climber’s success probability on a peak like Aconcagua, Denali, or Cho Oyu. Notably, ignoring any one of them pushes failure risk up dramatically.
The Right Month and Weather Window
Every major peak has a narrow window of high-success months and a wider window of low-success or unclimbable months. Generally, the gap between optimal and sub-optimal timing on Aconcagua is roughly 7 percentage points (January vs February). Specifically, on Everest, mid-May summits show meaningfully higher success than early-May or late-May. Notably, on Denali, June 1-20 is the optimal window. Earlier in May means colder and more weather hold-days; later in July means soft snow and crevasse opening.
What this means. For Kilimanjaro and Mera Peak, the right months are January-February and June-October (between monsoons). For Aconcagua, January over February. Specifically, for Everest and Lhotse, the spring window peaks in mid-May. Notably, the cost-benefit of premium-window timing usually outweighs off-peak savings — booking the right month matters more than booking the right operator on most peaks.
Trip-planning takeaway: Identify the optimal 2-3 week window for your peak and build the rest of the trip around it. Generally, do not flex on dates to accommodate other planning. Notably, the right month is the cheapest decision that improves your summit odds the most.
The Normal Route Premium
On every major peak, the Normal Route shows the highest success rate by a meaningful margin. Generally, the spread is sometimes dramatic. Specifically, on Aconcagua, Normal Route runs 47 percent while the South Face Messner Route runs 18 percent. On Everest, the South Col and North Col routes are within 5 percentage points of each other. The West Ridge and other technical routes run at 5-10 percent success rates. Notably, on Denali, West Buttress (51 percent) is meaningfully higher than Cassin Ridge (sub-30 percent) or Messner Couloir.
Why the Normal Route premium exists. Two reasons. Generally, lower technical demands mean fewer skills required at the limit of fatigue and altitude. Specifically, infrastructure builds up around the most-climbed route. Fixed ropes, rescue access, and weather forecasting all tune to the standard route. The social presence of other parties moving on the same line further reinforces the Normal Route advantage. Notably, even on technical Alps peaks like the Matterhorn, the Hörnli Ridge (Normal Route) carries advantages. Guides, rescue access, and gear stashes are all present on the Normal Route in ways that more technical routes lack.
Trip-planning takeaway: Choose the Normal Route on your first attempt of any peak. Generally, reserve technical routes for follow-up attempts after a successful Normal Route summit. Notably, climbers who attempt technical routes as their first ascent of a major peak succeed at fractional rates.
Guided vs Independent
Guided climbers summit at meaningfully higher rates. Generally, the gap typically runs 15-25 percentage points on major peaks. Specifically, Aconcagua guided success runs 51 percent vs 29 percent for independents. On Kilimanjaro, guided KPAP-member operators run 65-85 percent while independent self-organised treks (rare and discouraged) drop to roughly 30-45 percent. Notably, the gap on Mont Blanc is among the largest. IFMGA-guided climbers succeed at roughly 65 percent while independent first-time climbers run closer to 35 percent.
Why the gap exists. Three main reasons. Generally, guides enforce acclimatisation schedules and conservative rest days. Specifically, guides make real-time judgment calls on weather windows and turnaround decisions. Notably, guides carry emergency equipment and coordinate rescue logistics. They also bring institutional pattern-matching to common failure modes — a guide has seen the same exhaustion patterns on hundreds of climbers.
The independent-climber caveat. Independent climbers who follow guided protocols — mandatory rest days, conservative ascent, proper acclimatisation schedule — show outcomes much closer to guided climbers. Generally, the gap exists because most independent climbers do not enforce the discipline guides do. Specifically, “I have flexibility” is the most common reason independent climbers fail, when that flexibility gets used to ascend prematurely. For operator selection detail, see our mountaineering operators hub.
The Prior Altitude Effect
Experience level is the single strongest predictor of individual climber success once route and timing are controlled. Generally, on Aconcagua’s Normal Route, first-time high-altitude climbers (no prior 5,000m+) succeed at 24 percent. Climbers with a prior 5,000-6,000m summit (Kilimanjaro, Mount Kenya, Pico de Orizaba) succeed at 38 percent. Climbers with a prior 6,000m+ summit (Denali, Mera Peak) succeed at 52 percent. Specifically, repeated high-altitude climbers with multiple prior 6,500m+ peaks succeed at 61 percent. That’s more than 2.5x the rate of altitude novices on the same mountain.
Why prior altitude matters more than prior fitness. Altitude tolerance is not predicted by sea-level fitness. Generally, even elite endurance athletes can develop acute mountain sickness, HAPE, or HACE at altitudes they have not previously visited. Specifically, prior exposure to altitudes 1,000-2,000m below your target gives you a known acclimatisation profile that helps you and your guide make better scheduling decisions. Notably, this is why the proper progression sequence is built into experienced climber recommendations. Kilimanjaro before Aconcagua, Aconcagua before Denali, and Denali before Everest is the standard ladder.
Trip-planning takeaway: Climb at least one peak 1,000-2,000m below your target before attempting it. Generally, the most successful Everest climbers spent 1-3 years on the 8,000m progression peaks (Cho Oyu, Manaslu) before booking Everest. Notably, for more on the progression sequence, see our Aconcagua vs Denali vs Elbrus first-big-mountain guide.
Vinson Massif — The Highest Success Rate
Vinson has the highest success rate of any major commercial peak. Generally, the rate reflects climber self-selection. Only experienced and well-funded climbers reach Vinson at all, given the $48,000-$58,000 cost and ALE flight monopoly. Specifically, once you arrive at Union Glacier, the climb itself is technically straightforward. The standard 16-day glacier expedition has weather as the only meaningful challenge. Notably, the dominant cause of failed Vinson attempts is multi-day weather hold extending the trip past climbers’ available window. Full Vinson success rate data →
Island Peak — The Nepal Trekking-Peak Gateway
Island Peak is the most-summited 6,000m peak in Nepal and the standard introduction to Himalayan glacier and fixed-rope climbing. Generally, success rates run 75-85 percent on the 18-day commercial expedition that combines EBC trek with summit attempt. Specifically, the summit’s short technical headwall is the most common turnaround point. Climbers with limited prior fixed-rope experience sometimes turn back at the bergschrund crossing. Notably, Island Peak makes an excellent test peak for Everest aspirants. Full Island Peak success rate data →
Mount Elbrus — Highest Success of the Seven Summits
Elbrus has the highest summit success rate of any Seven Summit peak. Generally, this reflects three things. The cable car infrastructure that skips the lower 1,800 metres, the snowcat options that compress the summit-day timing, and the established Russian guiding chain. Specifically, the dominant cause of failed Elbrus attempts is sudden weather rather than altitude itself. Elbrus’s twin summits sit exposed to the broader Caucasus weather systems. Notably, post-2022 sanctions have complicated Western climber access but the on-mountain success rates remain consistent. Full Elbrus success rate data →
Mount Kilimanjaro — The Big-Volume Success Story
Kilimanjaro’s headline success rate of 65 percent hides one of the largest within-mountain success rate spreads in commercial climbing. Generally, the 8-day Lemosho route runs approximately 85 percent success while the 5-day Marangu route runs approximately 30 percent. Specifically, KPAP-member operators consistently outperform non-KPAP operators. Notably, the single biggest predictor of Kilimanjaro success is route days (more days = better acclimatisation). For full pattern analysis, see our companion why Kilimanjaro climbers fail investigation. Full Kilimanjaro success rate data →
Mera Peak — Highest Nepalese Trekking Peak
Mera Peak is the highest Nepalese trekking peak at 6,476m and a popular Everest precursor. Generally, success rates run 60-70 percent on the standard 18-day commercial expedition. Specifically, the climb combines a long approach trek with a glacier summit day that involves moderate fixed-rope sections. Notably, common turnaround reasons are altitude illness and weather, with the summit day’s long pre-dawn start being a critical timing point. Full Mera Peak success rate data →
Carstensz Pyramid — The Helicopter Approach
Carstensz Pyramid’s success rate reflects a unique combination: short technical climbing (Class 4-5 rock with fixed ropes), helicopter approach (since 2026 the standard option), and self-selected experienced commercial climbers. Generally, climbers who reach Carstensz base camp summit at approximately 75 percent. Specifically, the lower headline 60 percent rate folds in expeditions cancelled by Indonesian permit issues or weather windows that prevent the helicopter approach. Notably, see our Carstensz operators guide for the operator landscape. Full Carstensz success rate data →
Mont Blanc — The Alpine Classic
Mont Blanc’s headline 58 percent success rate disguises a wide spread by guide status. Generally, IFMGA-guided climbers succeed at 65-70 percent. Specifically, independent first-time alpine climbers run closer to 35-40 percent. Notably, the dominant failure modes are weather windows and rockfall. Mont Blanc has the most variable summit-day weather of any major Alpine peak. The Grand Couloir rockfall has caused regulatory closures while increasingly demanding early-morning timing. Full Mont Blanc success rate data →
Mount Rainier — The American Mountaineering School
Rainier is the standard American mountaineering school peak. Generally, success rates on the Disappointment Cleaver route (the dominant guided route) run 50-60 percent. Specifically, the four-day RMI program runs roughly 55 percent. Notably, the failure modes are remarkably consistent. Climbers who turn back typically do so for one of three reasons. Weather and route conditions drive about 40 percent of turnarounds, altitude illness or exhaustion about 35 percent, and fitness limits about 25 percent. Full Rainier success rate data →
Denali — The Cold-Weather Glacier Expedition
Denali’s 51 percent success rate reflects the mountain’s unique cold-weather demands. Generally, the West Buttress route is the dominant guided line; the more technical routes (Cassin Ridge, Messner Couloir, West Rib) run at fractional rates. Specifically, the dominant failure modes are weather hold-days that exhaust expedition time budgets and altitude illness at high camp. Notably, the 1:2 guide ratio (vs the 1:3 standard) meaningfully improves summit odds — premium operators consistently outperform standard-ratio operators by 10-15 percentage points. Full Denali success rate data →
Pico de Orizaba — Highest Peak in Mexico
Pico de Orizaba is the highest peak in Mexico and the standard introduction to glaciated peaks for North American climbers. Generally, success rates run 45-55 percent on the standard route from Piedra Grande. Specifically, the dominant failure modes are weather and abrupt elevation gain. High winds on the summit cone drive a meaningful share of turnarounds, and climbers go from Mexico City sea-level to 5,636m in 3-5 days. Notably, this is the peak that most clearly shows the prior-altitude effect — climbers with prior 5,000m+ experience succeed at roughly 65 percent. Full Orizaba success rate data →
Mount Shasta — California’s Iconic Volcano
Mount Shasta is the largest stratovolcano in the Cascade Range. Generally, success rates run 40-55 percent on the standard Avalanche Gulch route, with significant seasonal variation. Specifically, success rates are highest in May-June when snow conditions support cramponed ascent. Notably, late-season climbs (July-August) involve more scrambling and rockfall risk, and success rates drop accordingly. Full Shasta success rate data →
Chimborazo — The Bulge of the Earth
Chimborazo is technically the point on Earth’s surface farthest from its centre (thanks to Earth’s equatorial bulge). Generally, summit success rates run 40-50 percent on the standard route, with significant variability by ice and weather conditions. Specifically, climbers typically combine Chimborazo with Cotopaxi (5,897m). The Ecuadorian volcanic chain serves as a high-altitude acclimatisation progression. Notably, the lower 45 percent headline rate reflects the mountain’s frequent weather-window closures and the technical demands of the upper summit ridge. Full Chimborazo success rate data →
Aconcagua — The High-Altitude Hike
Aconcagua’s headline 39 percent success rate is one of the most-studied figures in commercial mountaineering. Generally, the subcategory breakdown is dramatic: Normal Route 47 percent, guided 51 percent, independent 29 percent, with prior altitude experience adding another 10-20 percentage points. Specifically, the dominant failure modes break out as follows. Altitude illness drives 38 percent of turnarounds. The Viento Blanco wind events that force descent from Camp Colera drive 27 percent, and exhaustion or insufficient fitness drives 18 percent. Notably, the 5-year rolling rate has declined from 46 percent (2005-2009) to 38 percent (2020-2024). Full Aconcagua success rate data →
Cho Oyu — The Most Accessible 8000er
Cho Oyu has the highest success rate of any 8000-metre peak. Generally, the rate reflects the standard “first 8000er” status. Most climbers approach Cho Oyu with prior 6,000m+ experience and proper commercial guidance. Specifically, the 1.3 percent fatality rate is the lowest of the 14 eight-thousanders. Notably, the headline 35 percent rate folds in some recent seasons disrupted by Chinese permit closures; in open seasons, operator-reported rates run 50-65 percent. Full Cho Oyu success rate data →
Manaslu — The Cho Oyu Substitute
Manaslu is the standard “first 8000er” alternative when Cho Oyu is closed. Generally, success rates run 30-50 percent on the standard route, depending on weather and snow conditions. Specifically, autumn 2022 and 2024 saw success rates near 90 percent on premium operators in optimal conditions. Notably, the dominant failure modes are avalanches (Manaslu is the most avalanche-exposed 8000er), high-altitude weather windows, and base-camp overcrowding when Cho Oyu is closed. Full Manaslu success rate data →
Lhotse — The 4th-Highest Peak on Earth
Lhotse shares its lower route with Everest — climbers traverse the Khumbu Icefall and Western Cwm to Camp 3, then split off for the Lhotse Couloir summit. Generally, success rates run 30-40 percent overall, higher among the Everest-paired-summit cohort. Specifically, the dominant failure modes mirror Everest’s — summit-day timing, oxygen logistics, and weather windows. Notably, the increasing number of climbers attempting an Everest-Lhotse double summit has lifted Lhotse’s success rates in recent seasons. Full Lhotse success rate data →
Mount Everest — Where Operator Choice Matters Most
Everest’s headline 29 percent success rate is a weighted historical average. Generally, modern commercial expeditions run much higher — premium operators routinely report 65-85 percent success rates, while budget operators sometimes drop to 30-40 percent. Specifically, the 40-point gap between premium and budget Everest operators is among the largest in commercial mountaineering. Notably, the dominant failure modes are documented in our companion Everest summit-day failures investigation — time-budget overruns, queue exposure, and oxygen failures. Full Everest success rate data →
Matterhorn — Lower Alpine, Higher Technical
The Matterhorn is an outlier — relatively modest altitude (4,478m) but a success rate that runs 25-35 percent because the technical demands are sustained throughout. Generally, the Hörnli Ridge involves Class 4-5 climbing on rotten rock with significant exposure. Specifically, weather windows are short and conditions deteriorate rapidly. Notably, IFMGA-guided climbers succeed at 50-60 percent while independent climbers run closer to 15-25 percent — one of the largest guided/independent gaps in commercial mountaineering. Full Matterhorn success rate data →
Dhaulagiri I — The White Mountain
Dhaulagiri (Tier II 8000er) has lower success rates than the commercial “first 8000ers” because its avalanche-exposed route demands more weather-window discipline. Generally, success rates run 20-35 percent depending on season conditions. Specifically, commercial guiding is smaller-scale than on Everest or Manaslu. Notably, climbers attempting Dhaulagiri typically come with prior 8000m experience. Full Dhaulagiri success rate data →
Makalu — The Black Pyramid
Makalu (Tier III 8000er) is technically more demanding than Everest’s South Col route. Generally, success rates run 20-30 percent on the standard route. Specifically, the dominant failure modes are the sustained steep terrain of the upper ridge and weather windows that can shut down summit attempts for days. Notably, Makalu is sometimes called the “honest 8000er”. It is a test peak that separates climbers ready for Tier I-II peaks from those who relied on commercial infrastructure. Full Makalu success rate data →
Kangchenjunga — The 3rd-Highest Peak
Kangchenjunga is the world’s third-highest mountain and one of the most remote major peaks. Generally, summit success rates run 15-25 percent on the standard route. Specifically, the long approach, weather exposure, and the upper ridge’s sustained terrain combine to make Kangchenjunga harder than its raw altitude suggests. Notably, climbers attempting Kangchenjunga are typically experienced 8000m mountaineers, but the success rate reflects the demands of the route itself rather than the cohort’s experience. Full Kangchenjunga success rate data →
Annapurna I — The Deadliest 8000er
Annapurna I has the lowest success rate among commercial 8000m attempts and the highest fatality rate. Generally, summit success rates run 15-20 percent. Specifically, the dominant failure modes are avalanche-driven weather window closures and exhaustion from the long approach. Annapurna has fewer stable periods than peaks where summit timing is wind-dependent. Notably, climbers attempting Annapurna are typically among the most experienced 8000m mountaineers, and the success rates still hover at 17 percent. Full Annapurna success rate data →
Nanga Parbat — The Killer Mountain
Nanga Parbat’s success rates run 15-20 percent on the Diamir Face standard route. Generally, the lower numbers reflect avalanche exposure, weather windows that can close for weeks, and the regional security situation that complicates rescue logistics. Specifically, the 2013 Diamir Base Camp terrorist attack remains a unique factor in the mountain’s planning calculus. Notably, success rates on Nanga Parbat correlate strongly with prior Karakoram experience. Climbers attempting it as their first Pakistani 8000er have particularly low success rates. Full Nanga Parbat success rate data →
K2 — The Savage Mountain
K2 has the lowest commercial success rate of any major peak. Generally, summit success runs 10-18 percent depending on season conditions. Specifically, the Bottleneck (an overhanging serac feature at approximately 8,200m) is the dominant technical and objective hazard on the standard Abruzzi Spur route. Notably, recent commercial expansion of K2 climbing has not increased the success rate the way commercial infrastructure increased Everest success. K2’s combination of technical demands and weather windows resists commercialisation. Full K2 success rate data →
Peak-Specific Success Rate Pages
Each major peak has its own detailed success rate page covering month-by-month rates, route-by-route comparison, guided/independent breakdown, experience-level analysis, turnaround reasons, rescue frequency, and historical trends. Generally, the pages below contain disaggregated data not summarised on this hub. Notably, peaks are ordered by impressions volume (the most-searched peak success rate queries first).
Summit Success Rate FAQ
What is a summit success rate?
A summit success rate is the percentage of climbers who reach the actual summit of a mountain. The denominator is climbers who attempted the peak from base camp or trailhead in a given season. Success is defined as reaching the official summit, not a false summit or partial high point. The rate is calculated from climbers who obtained a legal climbing permit. Turnaround decisions include weather holds, altitude illness, voluntary retreats, and operator-mandated turnarounds. Rescue incidents are tracked separately from failed-summit attempts. Operator-reported success rates can run meaningfully higher than overall park-wide rates because they capture only the operator’s clients — a self-selected, better-prepared group.
Which mountain has the lowest summit success rate?
K2 at approximately 14 percent is the lowest cumulative summit success rate among major commercial peaks. The rate reflects three factors. The mountain’s severe technical demands include the Bottleneck serac feature. Narrow weather windows and the relative inexperience of some recent commercial climbers attempting K2 as their first or second 8000m peak round out the picture. Annapurna I (17 percent), Nanga Parbat (16 percent), and Kangchenjunga (20 percent) round out the lowest tier — all Tier I or Tier II 8000m peaks. The lowest success rates correlate strongly with the highest fatality rates — these are the Killer Peaks of the 14 eight-thousanders.
Which mountain has the highest summit success rate?
Among commercially-guided peaks, Vinson Massif in Antarctica has the highest summit success rate at approximately 95 percent. This reflects three things. ALE’s monopoly of operators, the self-selected climber base (typically experienced and well-funded), and the relatively short technical climb once the long Antarctic logistical chain is complete. Island Peak in Nepal sits at approximately 80 percent. Mount Elbrus runs 72 percent, Mount Kilimanjaro and Mera Peak at 65 percent each, and Carstensz Pyramid at 60 percent round out the top tier. The highest success rates correlate with peaks that combine moderate altitude demands, good commercial guiding infrastructure, predictable weather windows, and relatively non-technical standard routes.
Why do guided climbers have higher success rates than independent climbers?
Three main reasons. Guided climbers benefit from enforced acclimatisation schedules, real-time guide judgment on weather windows, and rescue coordination support. Guides make conservative turnaround calls that maximise long-term success at the cost of individual-attempt aggressiveness. The gap typically runs 15-25 percentage points on major peaks. For example, Aconcagua guided success runs about 51 percent vs 29 percent for independents. Kilimanjaro guided runs 65 percent vs roughly 45 percent for independent self-organised treks. Independent climbers who mirror guided protocols (rest days, conservative ascent, proper acclimatisation schedule) show much better outcomes than the unstructured-independent baseline.
How does month and timing affect summit success rates?
Significantly. Every major peak has a narrow window of high-success months and a wider window of low-success or unclimbable months. On Aconcagua, January summit bids show 7 percentage points higher success than February (better weather windows, fewer Viento Blanco events). On Everest, mid-May summits show meaningfully higher success than early-May or late-May. On Denali, June 1-20 is the optimal window. Kilimanjaro has two clear windows — January-February and June-October — separated by monsoon seasons that drop success rates sharply. The cost-benefit of premium-window timing usually outweighs the costs of off-peak savings — booking the right month often matters more than booking the right operator.
How does route choice affect summit success?
Massively. On every major peak, the Normal Route shows the highest success rate by a meaningful margin. On Aconcagua, the Normal (Northwest) Route runs 47 percent while the South Face Messner Route runs 18 percent. On Everest, the South Col (Nepal) and North Col (Tibet) routes are within 5 percentage points of each other. The West Ridge and other technical routes run at 5-10 percent success rates. On Denali, West Buttress (51 percent) is meaningfully higher than Cassin Ridge (sub-30 percent) or Messner Couloir. The Normal Route premium reflects both lower technical demands and the greater support infrastructure that builds up around the most-climbed route.
Do summit success rates trend over time?
Yes, in measurable ways. Aconcagua’s 5-year rolling average has declined from 46 percent (2005-2009) to 38 percent (2020-2024). The drop reflects shorter reliable weather windows, glacier recession on the Polish Glacier route, and increased permit holder volume diluting the experienced-climber baseline. Everest’s success rate has gradually increased from approximately 18 percent in the 1990s to approximately 65 percent in recent seasons (per commercial-operator data). The rise reflects improved fixed-rope infrastructure, oxygen logistics, and weather forecasting. The trends move in different directions for different peaks. Climate change reduces success on glaciated peaks, while commercial infrastructure expansion increases it on the most-commercialised peaks.
How are summit success rates measured and verified?
Sources vary by peak. The Himalayan Database (Salisbury/Hawley) is the authoritative source for Himalayan and Karakoram peaks, with data collected from each season’s expeditions. In Aconcagua, the Mendoza Provincial Government tracks permits issued and summits reached. On Denali, the U.S. National Park Service reports through its concessionaire system. On Kilimanjaro, Tanzania National Parks Authority reports gate data, though success rates are best-tracked by KPAP-member operators. Operator-reported success rates can be 10-20 percentage points higher than park-wide rates. The reason: they reflect only the operator’s clients (a self-selected, better-prepared group) rather than all permit holders. We use park-wide rates where available and clearly mark operator-specific data.
Sources and Methodology
Data Sources
This investigation aggregates data across 11 authoritative sources:
- The Himalayan Database (himalayandatabase.com) — Salisbury/Hawley. The authoritative archive for Himalayan and Karakoram peaks.
- Aconcagua Provincial Park Authority — Mendoza Provincial Government permit and summit records.
- U.S. National Park Service, Denali — annual climbing reports through the concessionaire system.
- Tanzania National Parks Authority (TANAPA) — Kilimanjaro gate data.
- KPAP (Kilimanjaro Porters Assistance Project) — operator-tracked success rates for member operators.
- Alan Arnette’s annual Everest by the Numbers — independent analyst review of Everest seasons.
- ExpedReview 2026 pricing and success rate data — Spring 2026 Everest season analysis.
- American Alpine Club Accident Reports — for North American peaks.
- Operator-published success rates — 8K Expeditions, Seven Summit Treks, Adventure Consultants, Furtenbach Adventures, RMI Expeditions, Madison Mountaineering, IMG.
- Wilderness Medical Society — for altitude illness rate context.
- Mendoza Provincial Government permit data — Aconcagua climbing season statistics.
Methodology note. Where operator-reported rates differ meaningfully from park-wide rates, we use the park-wide rate as the headline figure. The park-wide rate reflects the broader cohort of climbers attempting the peak, and we call out operator-specific data separately. Numbers reflect rolling 5-year averages where available, with single-season outliers noted. Climbers with verified expedition results willing to contribute data are invited to contact our editorial team. Published: January 15, 2026. Last updated: May 27, 2026. Next scheduled review: November 2026.
Related Planning Resources
Plan Around Facts, Not Folklore
Summit success rates are knowable, plannable, and improvable. Generally, the four drivers above — timing, route, guide status, prior experience — are all under climber control. Notably, climbers who optimise across all four typically double their odds versus the published baseline. Pick your peak, then read the dedicated success-rate page for the disaggregated data.
Browse Peak Pages →