42km du Mont-Blanc - Elevation Profile, Aid Stations and Cutoffs
42km du Mont-Blanc is a 42 km ultra-trail with around 2,540 m of elevation gain, starting in Chamonix, France. The overall cutoff is 11 hours 20 minutes. The highest point on the course is Aiguillette des Posettes at 2,200 m.
- Distance
- 42 km
- Elevation
- +2,540 m -2,540 m
About 60 m of climb per km
- Highest point
- 2,200 m
Aiguillette des Posettes
Next edition Sun 27 Jun 2027 · 06:45
in about 9 months- Start
- Winner ~3h33 3h33 after the start
- Median finisher 2026 median 7h45 after the start
- Cutoff 11h20 after the start
Race details
Explore the 42km du Mont-Blanc course, kilometre by kilometre
Built from the organiser's course data, set to the 06:45 start.
- Map Interactive map
- Profile Elevation profile
- Checkpoints Checkpoints and cutoffs
- Weather Race-day weather
The biggest climb between checkpoints gains around 720 m from Le Tour (km 13.5) to Aiguillette des Posettes (km 18). The steepest sustained section on the elevation profile averages about 24% over roughly 2.7 km around km 15. Crew access is allowed at Le Tour (13.5 km), Vallorcine (23.5 km) and La Flegere (34.2 km).
Data is approximate and courses change between editions - always verify against the official race guide.
Enter a goal finish time and see estimated arrivals vs checkpoint cutoffs.
Plan against barriersOne Strava connection reads your last 90 days and estimates your finish on this course. Free, no plan needed.
Elevation profile
Course math
Four numbers worked out from this course's distance, elevation and checkpoints.
TrailMath effort-km
80 effort-km
About 7 h for a mid-pack finisher (index 500). Not a pacing guarantee.
Distance + gain ÷ 100 + loss ÷ 200, beside ITRA's gain-only km-effort. Model TM1.0.
How TrailMath works →UTMB Index category
50K
67 km-effort (distance + gain ÷ 100). Calculated from the course figures, not an official classification.
Estimate your UTMB Index →Biggest climb section
+720 m
Le Tour → Aiguillette des Posettes · km 13.5–18
The largest gain between two checkpoints, not one continuous climb.
Le Tour cutoff: Sun 10:50
Plan against barriers →Biggest descent section
−930 m
Aiguillette des Posettes → Vallorcine · km 18–23.5
The largest loss between two checkpoints. ITRA's km-effort ignores descent; TrailMath counts it: 80 km-effort.
Open in GPX Explorer →Share this race
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42km du Mont-Blanc · 2026
Finish times, 2026 edition
1,999 runners finished. Half of them took longer than 7:45:13. That left the median finisher 3:34:35 inside the 11h20 cutoff.
Median finish
7:45:13
Half of the 1,999 finishers were still out there at this point.
3:34:35 in hand before the 11h20 cutoff
Average 7:41:36, 0:03:37 quicker than the median: a fast front pulls it down.
The start line
Men and women
Two medians on the same scale. The bars run from the start to the cutoff, so the gap between them is the gap in time.
Men
7:35:37
median finish; average 7:35:28
1,545 finishers, 77% of the field
Women
8:07:07
median finish; average 8:02:27
454 finishers, 23% of the field
0:31:30 separates the two medians, across 1,545 men and 454 women.
Finish time by age group
Every track runs from the start to the 11h20 cutoff, so the empty part of a bar is the time that group's median finisher still had. Men and women are drawn on the same scale.
| Age | Median finish | Median against the cutoff | Finishers |
|---|---|---|---|
| ES | 6:59:44 | 30 | |
| SE | 7:11:57 | 643 | |
| M0 | 7:31:39 | 263 | |
| M1 | 7:49:25 | 214 | |
| M2 | 8:03:10 | 151 | |
| M3 | 8:28:23 | 125 | |
| M4 | 8:27:15 | 78 | |
| M5 | 8:43:19 | 31 | |
| M6 | 8:31:52 | 10 - small sample, read with care |
| Age | Median finish | Median against the cutoff | Finishers |
|---|---|---|---|
| ES | 7:09:44 | 10 - small sample, read with care | |
| SE | 7:59:02 | 219 | |
| M0 | 8:14:54 | 90 | |
| M1 | 8:25:03 | 64 | |
| M2 | 8:19:14 | 38 | |
| M3 | 8:49:21 | 19 - small sample, read with care | |
| M4 | 7:59:16 | 10 - small sample, read with care | |
| M5 | 8:26:34 | 4 - small sample, read with care |
Full bar: 20 finishers or more. Tick alone: fewer than 20, too few for a median to say much. The shaded row is the biggest group.
Where the finishers came from
85% of the finishers came from France alone.
| Nation | Finishers | Share |
|---|---|---|
| France FR | 1,701 85.1% | |
| Belgium BE | 60 3.0% | |
| United Kingdom GB | 58 2.9% | |
| Spain ES | 27 1.4% | |
| Switzerland CH | 17 0.9% | |
| Italy IT | 14 0.7% | |
| Sweden SE | 10 0.5% | |
| Germany DE | 7 0.4% | |
| Netherlands NL | 7 0.4% | |
| Norway NO | 6 0.3% | |
| Portugal PT | 6 0.3% | |
| United States US | 6 0.3% | |
| Australia AU | 5 0.3% | |
| Brazil BR | 5 0.3% | |
| Poland PL | 5 0.3% | |
| Canada CA | 4 0.2% | |
| Denmark DK | 4 0.2% | |
| Greece GR | 4 0.2% | |
| Ireland IE | 4 0.2% | |
| China CN | 3 0.2% | |
| Colombia CO | 3 0.2% | |
| Algeria DZ | 3 0.2% | |
| Lithuania LT | 3 0.2% | |
| Mexico MX | 3 0.2% | |
| Curaçao AN | 2 0.1% | |
| Bulgaria BG | 2 0.1% | |
| Finland FI | 2 0.1% | |
| Hungary HU | 2 0.1% | |
| Kenya KE | 2 0.1% | |
| Luxembourg LU | 2 0.1% | |
| Latvia LV | 2 0.1% | |
| Philippines PH | 2 0.1% | |
| South Africa ZA | 2 0.1% | |
| Argentina AR | 1 0.1% | |
| Austria AT | 1 0.1% | |
| Costa Rica CR | 1 0.1% | |
| Estonia EE | 1 0.1% | |
| Egypt EG | 1 0.1% | |
| Indonesia ID | 1 0.1% | |
| Japan JP | 1 0.1% | |
| Kyrgyzstan KG | 1 0.1% | |
| South Korea KR | 1 0.1% | |
| Morocco MA | 1 0.1% | |
| Malta MT | 1 0.1% | |
| New Zealand NZ | 1 0.1% | |
| Romania RO | 1 0.1% | |
| Thailand TH | 1 0.1% | |
| Tunisia TN | 1 0.1% | |
| Ukraine UA | 1 0.1% | |
| 39 other nations 29 other nations 19 other nations 9 other nations | 92 4.6% 46 2.3% 22 1.1% 9 0.5% |
Showing 20 of 49 nations. Showing 30 of 49 nations. Showing 40 of 49 nations. Showing 49 of 49 nations.
Bar length is against the largest nation. The smallest counts are drawn at a minimum visible width, so their bars are not to scale.
How these numbers were computed
These are times for runners who finished. They exclude everyone who started and did not, so they describe how long finishing took, not how long the race takes. Bands with only a handful of finishers move a lot from one edition to the next.
We plot the median, not the average. A handful of very quick runners drags the average well below the time half the field actually beat, so the median is the honest number to plan against.
Nationality here shows who travels to this race, not who runs it best. That alone is why a host nation tops almost every list.
Computed from the full official results, verified September 29, 2026 - Official results
Ask the course
Ask 42km du Mont-Blanc anything about climbs, pacing, crew or cutoffs.
Answers come from this course's data, your plan and your training.
Which climb should I respect most?
Le Tour to Aiguillette des Posettes: +720 m over 4.5 km, from km 13.5. Hike the steep sections at an effort you could hold for hours - the race is decided after this climb, not on it.
Where can my crew meet me?
Le Tour, km 13.5 - the first of 3 crew points. The next is Vallorcine, km 23.5. Have them bring warm layers: the course tops out at 2,200 m, in June.
Is 7h a realistic finish for me?
7h would put you in the faster half of 2026 finishers - the median was 7:45:13. It means holding 10:00/km overall.
The Coach answers that once it can see your training.
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Example answer
Your long runs peak at 15 km, so the plan builds to 4-hour long runs. Cutoff buffer at Vallorcine: 2h60.
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Aid stations and checkpoints
| Checkpoint | Km | Cumulative gain (m) | Cumulative loss (m) | Cutoff | Crew | Drop bag |
|---|---|---|---|---|---|---|
| Start - Chamonix | 0 | 0 | 0 | - | - | - |
| Argentiere | 10.5 | 420 | 150 | - | No | No |
| Le Tour | 13.5 | 730 | 210 | Sun 10:50 | Yes | No |
| Aiguillette des Posettes | 18 | 1,450 | 250 | - | No | No |
| Vallorcine | 23.5 | 1,450 | 1,180 | Sun 13:35 | Yes | No |
| Bas du Plagnolet | 30.5 | 1,970 | 1,520 | - | No | No |
| La Flegere | 34.2 | 2,480 | 1,540 | Sun 16:35 | Yes | No |
| Charlanon | 36.8 | 2,540 | 1,690 | - | No | No |
| Chamonix (Finish) | 42 | 2,540 | 2,540 | Sun 18:05 | Yes | No |
Data is approximate and courses change between editions - always verify against the official race guide. Source: official race guide, verified September 29, 2026 - Official race website
FAQ
How much elevation gain does 42km du Mont-Blanc have?
42km du Mont-Blanc has around 2,540 m of cumulative elevation gain and 2,540 m of loss over 42 km.
What is the cutoff time for 42km du Mont-Blanc?
The overall 42km du Mont-Blanc cutoff is 11 hours 20 minutes, with intermediate time barriers at major checkpoints. Winning times are typically around 4 hours.
How long is 42km du Mont-Blanc?
42km du Mont-Blanc covers approximately 42 km, starting in Chamonix, France.
What is the highest point of 42km du Mont-Blanc?
The highest point of 42km du Mont-Blanc is Aiguillette des Posettes at 2,200 m.
How many aid stations does 42km du Mont-Blanc have and which allow crew?
The checkpoint table lists 7 major aid points between the start and the finish. Crew access is allowed at Le Tour (13.5 km), Vallorcine (23.5 km) and La Flegere (34.2 km).
Training for this race?
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