UTMB 2026 Cutoff Times: The Math Behind 46 Hours¶
The gun goes off at 5:45 PM on August 28. Nine days from now, you will be running out of Chamonix in the last of the afternoon light, and the next time you see that square is 46 hours and 45 minutes later, or not at all.
Most runners in taper have already found the official cutoff chart. What follows, usually around 11 PM, is not the question "what are these numbers" but "is the clock working for me or against me."
The answer is determined almost entirely by the first checkpoint.
The full 2026 cutoff picture¶
Official cutoff times from montblanc.utmb.world. The race starts at 5:45 PM on Friday August 28 in Chamonix, with 46 hours and 45 minutes total allowance across 13 manned checkpoints in France, Italy, and Switzerland.
| Checkpoint | Km | Country | Clock cutoff | Elapsed | Avg km/h from start |
|---|---|---|---|---|---|
| Saint-Gervais | 22.8 | FR | Fri 22:00 | 4h 15m | 5.4 |
| Les Contamines | 32.5 | FR | Sat 00:00 | 6h 15m | 5.2 |
| La Balme | 41.1 | FR | Sat 02:00 | 8h 15m | 5.0 |
| Les Chapieux | 52.3 | FR | Sat 05:15 | 11h 30m | 4.6 |
| Lac Combal | 69.5 | IT | Sat 10:00 | 16h 15m | 4.3 |
| Courmayeur | 83.4 | IT | Sat 13:15 | 19h 30m | 4.3 |
| Arnouvaz | 101.8 | IT | Sat 18:15 | 24h 30m | 4.2 |
| La Fouly | 116.3 | CH | Sat 22:30 | 28h 45m | 4.1 |
| Champex-Lac | 130.4 | CH | Sun 02:30 | 32h 45m | 4.0 |
| Trient | 147.0 | CH | Sun 08:00 | 38h 15m | 3.8 |
| Vallorcine | 159.2 | FR | Sun 11:15 | 41h 30m | 3.8 |
| La Flégère | 170.6 | FR | Sun 14:45 | 45h 00m | 3.8 |
| Chamonix (Finish) | 177.6 | FR | Sun 16:30 | 46h 45m | 3.8 |
Look at the last column. Notice the direction it moves.
Why required pace decreases as the race progresses¶
The highest cumulative average required at any UTMB checkpoint is at the very first one: Saint-Gervais at km 22.8 asks 5.4 km/h from the gun. By Trient, that number has dropped to 3.8 km/h, and it holds there through the finish.
The race does not get harder by the clock. It gets more forgiving.
This is not a design error or an accident of how the cutoffs were set. The course structure produces it. The opening section from Chamonix to Saint-Gervais covers runnable terrain in the evening light, with roughly 1,100 meters of gain over 22.8 kilometers. The back half of the race is a different thing entirely: Grand Col Ferret at 2,537 meters, more total vertical per kilometer, and the second night pushing across the Swiss Alps into France. The cutoffs are calibrated to what the course asks.
Running 5.4 km/h on fresh legs in the early evening is a different physical task than running 3.8 km/h at 38 hours on legs that have already covered 147 kilometers. The cutoff designers understood this, and the numbers reflect it.
In concrete terms: 5.4 km/h is approximately 11:07 per kilometer. 3.8 km/h is approximately 15:47 per kilometer. The race requires 42 percent less speed from the gun at the back end than at the front. That is the structure of the clock, stated as a fact rather than a comfort.
The implication for a runner nine days out: clear Saint-Gervais, and the pace requirement stops tightening and starts easing. The gate you just cleared was the hardest one on the course by average speed from the start. Every checkpoint after it asks less.
Saint-Gervais: the first gate is the tightest¶
Saint-Gervais sits at km 22.8 with a cutoff of 10:00 PM Friday, 4 hours and 15 minutes from the gun. At 5.4 km/h required, it is the most demanding checkpoint in the race by cumulative average pace. Translated to trail running terms: approximately 11:07 per kilometer for the first 22.8 kilometers.
The section from Chamonix runs through Les Houches before the climb toward Saint-Gervais. The terrain is demanding, with roughly 1,100 meters of gain, but it is not the exposed alpine ground that defines the second half of the race. There are no high passes and no glacier crossings. The difficulty is the elevation gain coming early, before the legs have settled into the rhythm of a very long day.
Two things tend to work in a runner's favor here. First, the race starts with 2,500 runners and the energy of a starting line in Chamonix, which typically pulls the field through the opening section faster than the cutoff requires, not slower. Second, the 10:00 PM clock time gives a runner arriving in the early evening multiple hours of daylight before the cutoff window even becomes a consideration.
Runners who find themselves anywhere near the cutoff at Saint-Gervais should pay attention, because the alternative is making it and then not seeing a harder clock requirement for the rest of the race. Make Saint-Gervais within the window, and the tightest gate on the course is behind you. That is the structural shape of UTMB: hardest first, by the clock, then progressively more forgiving.
Courmayeur: the DNF capital, and what it means¶
Courmayeur arrives at km 83.4, with a cutoff of 1:15 PM Saturday, 19 hours and 30 minutes into the race. The required cumulative average is 4.3 km/h. By the clock, Courmayeur is one of the gentler checkpoints.
It is also where 17.7 percent of all UTMB DNFs occur, the highest concentration of any single checkpoint in the race. That figure comes from T8 race analysis across multiple editions. No other checkpoint accounts for as many races ending.
Those two facts are not in conflict. The DNF rate at Courmayeur is not produced by a cutoff wall. Runners arriving at Courmayeur under the time limit and then stopping represent the majority of that 17.7 percent. The data shows DNFs there clustering before the cutoff expires, not at it.
What Courmayeur has, that no other checkpoint on the course has, is infrastructure. It sits in Italy's Valle d'Aosta with crew access, drop bags, actual buildings, warm food, and people who drove hours to wait for you. After nineteen hours of running through France and across Col de la Seigne into Italy, through a full night on the trail, Courmayeur offers a genuine off-ramp. The community around any 100-plus-kilometer race understands that stopping is sometimes the right call. What the data shows is that Courmayeur is the place where that call gets made most often, not because the clock forces it, but because it is the most comfortable place to make it.
For a runner who reaches Courmayeur within the cutoff: you have covered more than half the race by distance. The first night is behind you. You have crossed one international border and the Col de la Seigne. The decision Courmayeur is asking is not mathematical. The math already cleared. What it is asking is whether you want to run into Switzerland.
Champex-Lac: the 94% line¶
Champex-Lac sits at km 130.4 with a cutoff of 2:30 AM Sunday, 32 hours and 45 minutes from the start.
The section between Courmayeur and Champex-Lac is the longest stretch of the race without a major crew point. It covers Grand Col Ferret at 2,537 meters, the highest point on the course, where runners cross from Italy into Switzerland. Coming down from the col into the Swiss Val Ferret, the trail passes La Fouly and eventually climbs up to the village perched at the edge of Lac Champex. The cumulative toll by this point: three countries, more than 130 kilometers, and 32-plus hours of movement.
Historical data from T8 shows that runners who leave Champex-Lac within the cutoff go on to finish 94 percent of the time.
Ninety-four percent. If you are out of Champex-Lac with time in hand, you are almost certainly finishing.
The remaining 47 kilometers include the Catogne climb, Trient, and the La Flégère ascent before the final descent into Chamonix. None of it is trivial. But the statistical picture is this clear: the 6 percent who do not finish from Champex-Lac are not stopped by the clock. They are stopped by injury, weather, and genuine emergencies that the math cannot account for. If pace is the question, Champex-Lac is the answer.
Runners who know this checkpoint by reputation often make it a deliberate mental target: get to Champex-Lac, and you are no longer running against the cutoff structure. You are finishing.
Reading your own budget¶
The checkpoint table above shows cumulative average pace from the gun. The table below shows something different: what each major leg asks on its own terms, between one checkpoint and the next.
| Leg | Distance | Elev. gain | Time budget | Segment km/h |
|---|---|---|---|---|
| Chamonix to Saint-Gervais | 22.8 km | ~1,100m | 4h 15m | 5.4 |
| Saint-Gervais to Les Contamines | 9.7 km | ~700m | 2h 00m | 4.9 |
| Les Contamines to Les Chapieux | 19.8 km | ~1,400m | 5h 15m | 3.8 |
| Les Chapieux to Courmayeur | 31.1 km | ~2,200m | 8h 00m | 3.9 |
| Courmayeur to La Fouly | 32.9 km | ~1,800m | 9h 15m | 3.6 |
| La Fouly to Champex-Lac | 14.1 km | ~600m | 4h 00m | 3.5 |
| Champex-Lac to Vallorcine | 28.8 km | ~1,200m | 8h 45m | 3.3 |
| Vallorcine to Chamonix | 18.4 km | ~800m | 5h 15m | 3.5 |
The opening segment at 5.4 km/h stands alone. After Saint-Gervais, no segment requires more than 3.9 km/h. The Champex-Lac to Vallorcine stretch, which crosses Catogne in the middle of the second night, allows 3.3 km/h across 28.8 kilometers. That is the most forgiving segment-pace in the race.
This table is where training data becomes directly useful. What pace do you hold on mountain terrain after 15 or 20 hours on your feet? Not road pace from a flat training route, but honest mountain movement after the first night. If that number sits above 3.5 km/h, the back half of this course is not the problem the cutoff structure is worried about.
The opening 22.8 kilometers are the check. That is where the clock is tightest. That is where your plan for August 28 needs to be clear.
Your training from the last several months already contains the answer. The long days, the vert, the back-to-back efforts: that data shows what you do when the legs are tired and the hours are stacking. The cutoff table gives it a target to check against.
Nine days out¶
Training is done. The window has closed, and the fitness in your legs now is the fitness you carry to the start.
What is worth doing in these nine days is reading your own record clearly. Not to second-guess any of it. To see what you built, measured against what the course is asking.
If your runs are already in Strava, the dashboard at navrun.app organizes that history without requiring a spreadsheet: time on feet across your longest efforts, vert accumulation over the block, how the training load moved across the weeks. The picture your training already holds is there, laid out across time. Connecting takes a minute; the data fills in on its own.
See you in Chamonix.