How long will 13.1 miles with 2,000 ft of climbing take? Finish time and pace per section from your flat pace, or the grade-adjusted pace a hilly result was worth.
Is 900 ft of elevation gain a lot for a run?
How long will 13.1 miles with 2,000 ft of climbing take? Finish time and pace per section from your flat pace, or the grade-adjusted pace a hilly result was worth.
On a 13.1-mile course with 900 ft of climbing and the same descent, a runner whose flat pace is 9:00 per mile finishes in 2:06:45 instead of 1:57:54: about 8.8 minutes more, on an average grade of 2.6%. Packed into a 10K, the same 900 ft costs about 9.4 minutes, so the climbing itself, not the distance, sets most of the bill. The calculator below is filled in with that course, the 9:00 pace and careful downhills (no speed-up on descents), using the energy cost of running measured by Minetti and colleagues. Whether it is a lot for you depends on your own pace: change it, the distance or the descent and press Calculate.
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Trail running pace for a course with climbs, worked out from your flat pace
A half marathon with 2,000 ft of climbing and the same descent, run at the effort of a 9:00 flat mile, takes 2:19:00. That is an average of 10:37 per mile, so the hills cost 1 min 37 s on every mile of the course. This trail running pace calculator gives that finish time from distance, elevation gain, elevation loss and your flat pace, turns a finish time on a hilly course into a grade-adjusted pace (GAP), and prices a single climb or descent. Miles and feet or kilometers and meters, with the other unit shown for reference.
Problem: a road pace says nothing about 2,000 feet of climbing
Solution: price every grade in energy, then in minutes
The calculator does not guess a fixed penalty per 100 feet. It uses the energy cost of running measured on a treadmill tilted from -45% to +45% by Minetti and colleagues (Journal of Applied Physiology, volume 93), whose ten subjects were fell runners. At every grade it picks the pace that costs the same energy per second as your flat pace.
What to enter for each of the three modes
- What do you want to calculate? - finish time from a flat pace (before the race), grade-adjusted pace from a finish time (after it), or the pace on one grade.
- Units - miles and feet, or kilometers and meters. Every distance, elevation and pace on the form uses the unit you pick.
- Downhills - careful (no speed-up, the default) or the full model saving.
- Course distance, elevation gain and elevation loss - from the race page, a map or your watch file. On a loop gain and loss are about equal; on a summit race the loss is 0.
- Flat sections - optional miles of road or valley floor with no climbing. They make the hilly part steeper, which is closer to how most mountain courses are built.
- Flat pace - minutes and seconds per mile or kilometer that you hold on a long, steady run on the flat. Seconds accept decimals such as 30.5.
- Finish time or grade - hours, minutes and seconds in the GAP mode, or a grade in percent (minus for downhill) in the one-grade mode. Then read the main figure, the tiles and the grade table.
Which mode and which downhill setting fits your question
The first row uses the default settings of the calculator. Every answer in the right-hand column comes from the same model, only the inputs differ.
| Your question | Mode | Downhills | What you get |
|---|---|---|---|
| How long will this trail race take me? | Finish time | careful | a conservative finish time and pace per section |
| I descend fast and train on technical ground | Finish time | full model | a best case; treat it as the floor, not the plan |
| Was this hilly race better than my road 10K? | Grade-adjusted pace | careful | the flat pace the effort was worth |
| What pace on a 6% hill repeat matches my tempo? | One grade | either (no effect uphill) | the pace and speed for the same effort |
| Point-to-point summit race | Finish time | either (loss = 0) | time for a climb-only course |
From a hilly 10K to a mountain 50K: eight results
Finish 1:00:31, average 9:46 per mile. The climbs take 34:08 at 11:01, the descents 26:23.
Finish 2:19:00, average 10:37. Km-effort 27.2.
Finish 2:03:10, average 9:24. The climbs do not change (1:19:57), the descents drop from 59:03 to 43:13 at 6:36 per mile. That gap of almost 16 minutes is the whole case for choosing the setting honestly.
Finish 5:16:25, average 12:05. Climbs 2:50:06 over 11.6 miles at 14:40, descents 1:56:19, flat 30:00.
Careful descents: 7:01:32. Full model: 6:06:11. On a long course the setting is worth almost an hour.
Finish 59:15 at 19:07 per mile on an average grade of 18.3%. Close to the point where most people hike.
GAP 8:44 per mile against a watch average of 10:18. Kept up over 13.1 flat miles, that effort is about a 1:54:30 half marathon.
That is the Mount Washington uphill race as listed by Minetti and colleagues. In metric mode, 58:20 on that course gives a GAP of 2:40 per km (4:17 per mile), from a watch average of 4:47 per km.
Pace per mile on climbs, by flat pace
Each cell is the pace that matches the effort of the flat pace in the first column, from the same model the calculator runs. Descents in the careful setting stay within 4 s of the flat pace down to -10%, so they are left out.
| Flat pace | +3% | +5% | +8% | +10% | +15% | +20% |
|---|---|---|---|---|---|---|
| 7:00 | 8:13 | 9:07 | 10:36 | 11:40 | 14:35 | 17:52 |
| 8:00 | 9:24 | 10:25 | 12:07 | 13:20 | 16:40 | 20:25 |
| 9:00 | 10:34 | 11:44 | 13:38 | 15:00 | 18:45 | 22:58 |
| 10:00 | 11:45 | 13:02 | 15:08 | 16:40 | 20:50 | 25:31 |
| 11:00 | 12:55 | 14:20 | 16:39 | 18:20 | 22:55 | 28:04 |
| 12:00 | 14:05 | 15:38 | 18:10 | 20:00 | 25:00 | 30:37 |
Where the model stops and your legs take over
Downhill speed is the weak spot, and the paper says so. Minetti and colleagues compared the model with real races. For nine uphill races the predicted climbing speed came out at 0.95 of the measured one on average. For five downhill races the model's top speed was 3.4 times what the best runners actually managed. Footing, braking and the risk of a fall set the pace downhill, not oxygen. That is why the careful setting is the default.
The fitted curve is slightly high on the flat. The measured cost of level running was 3.40 J/(kg·m), while the polynomial gives 3.6 at 0%. The calculator divides every grade by the curve's own flat value, so the ratios between grades stay consistent.
One average grade for the whole course. The hilly distance is split between climbing and descending in proportion to gain and loss, and both share one grade. A course with one brutal 30% wall and long gentle rollers will run differently from the same totals spread evenly.
Hiking, altitude and fatigue are outside the model. Above an average grade of about 20% the result warns you, because most runners walk there. Thin air, heat and the last hours of an ultra all come on top of what the grade costs, and none of them is in the numbers.
Trail pace questions, with the minutes worked out
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Calculator verified by the LiczGrupa.pl team
Content, formulas and results have been reviewed for accuracy and relevance by our team of specialists.
Reviewed by: Patryk Matyjasik