Trail running time estimator
Calculate how long it will take you to complete your next trail race. Enter the course data and your level to get an estimate with component breakdown.
Quick trail time reference
Typical vertical speed (climb)
- Beginner: 350–450 m/h
- Intermediate: 500–600 m/h
- Advanced: 700–800 m/h
- Elite: 900–1100 m/h
Ultra fatigue factor
- < 42 km: no penalty
- 42–80 km: +3–5% time
- 80–120 km: +8–12% time
- 120–170 km: +15–20% time
Race data
Estimated time
Race cutoff time
Flat time
Climb time
Descent time
Summary
Average pace
Climb rate
Descent rate
Effort-km
Factors applied
With this estimated time...
Frequently asked questions
How is the estimated time calculated?
The estimator uses a three-component model: flat time (based on your pace), climb time (based on your vertical ascent speed) and descent time. It then applies correction factors for terrain type and accumulated fatigue at long distances. This is the same approach used by professional trail running coaches.
How accurate is the estimator?
For trail races with reliable distance and elevation data, typical accuracy is ±10-15%. Factors like altitude, weather, your fitness on the day or downhill technique can affect the result. That's why we show an optimistic-conservative range.
What is vertical speed?
Vertical speed (m/h) measures how many meters of elevation gain you can climb per hour. A beginner runner climbs at around 400 m/h, while an elite can exceed 1000 m/h. It is one of the most important metrics in trail running because climbs consume most of the time in mountain races.
Why does the time increase disproportionately at ultra distances?
At distances over 42 km, the body accumulates muscular, digestive and mental fatigue that progressively slows the pace. This effect is called "ultra fatigue" and is normal: even elite runners slow down 15-20% in the final hours of an ultra trail. Our model applies a fatigue factor based on total distance.
How do I choose my runner level?
Beginner: your first trail or less than 1 year running in the mountains. Intermediate: you run trails regularly, you have completed a race of 20-40 km. Advanced: you compete regularly, you have finished ultras, you train 4-5 days/week. Elite: you place in the top positions, you train 6+ days/week, you have a high ITRA index.
What if I don't know the negative elevation (D−)?
If you don't know it, leave it equal to the positive elevation (D+). In most loop or point-to-point races, D+ and D− are very similar. They only differ significantly in races that finish at a very different altitude from the start.
How the time estimator works
This estimator calculates your race time using a three-component model adapted to trail running:
- Horizontal component: the time it takes you to cover the distance on flat ground, based on your base pace.
- Climb component: the additional time for climbing, calculated based on your vertical speed (meters/hour of positive elevation).
- Descent component: the descent time, which also adds time although less than climbing.
Two correction factors are applied on top of this base time:
- Terrain factor: a technical trail with rocks and roots is slower than a smooth trail. Skyrunning with ridges and scrambling is even slower.
- Ultra fatigue factor: beyond 42 km, the body progressively loses efficiency due to muscular, digestive and mental fatigue.
The result is a range (optimistic - conservative) because no model can precisely predict factors like weather, your fitness on the day, or time spent at aid stations.