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Grade-Adjusted Pace Calculator
Your flat pace & the grade
Estimate only: this calculator uses a simple linear grade rule (see the formula below). Real effort also depends on the surface, the wind and how steep the hill is.
Example: an 8:00 per mile runner on flat ground, on a steady 10% uphill grade, runs a grade-adjusted pace of 10:00 per mile.
Behind the numbers
How grade-adjusted pace is calculated
Running uphill costs extra energy, so the same effort produces a slower pace. This calculator uses a simple linear grade rule: uphill, your pace grows by about 2.5% for every 1% of grade; downhill, it shrinks by about 1.2% for every 1% of grade, up to 12% faster at most. It is a transparent estimate, not a lab measurement — Strava’s grade adjusted pace uses Minetti’s energy-cost curve instead, which gives a larger uphill penalty.
Uphill. For downhill, use (1 + 0.012 × grade%), with the factor never below 0.88. Example: 8:00 per mile × (1 + 0.025 × 10) = 8:00 × 1.25 = 10:00 per mile.
A few comparisons
Example adjusted paces
| Flat pace | Grade | Factor | Adjusted pace |
|---|---|---|---|
| 8:00 / mile | +5% uphill | × 1.125 | 9:00 / mile |
| 8:00 / mile | +10% uphill | × 1.25 | 10:00 / mile |
| 8:00 / mile | −5% downhill | × 0.94 | 7:31 / mile |
| 7:00 / mile | +8% uphill | × 1.20 | 8:24 / mile |
| 9:30 / mile | +12% uphill | × 1.30 | 12:21 / mile |
| 6:30 / mile | −10% downhill | × 0.88 | 5:43 / mile |
All values are computed with the formula above and rounded to the nearest second.
Run hills by effort, not by pace.
On a climb, hold the effort you would hold on flat ground and let the watch slow down — chasing your flat pace uphill is the fastest way to blow up a run.
Use grade-adjusted pace to compare hilly and flat runs. If your adjusted pace matches your usual flat pace, you ran just as well as usual.
Shorten your stride and lean slightly into the hill from your ankles, not your waist. Quick, light steps cost less energy than long lunges.
Downhill, stay relaxed and let gravity help, but do not overstride — on grades steeper than about 10% the braking cost cancels the speed gain.
Good to know
Your pace questions, answered.
What is grade-adjusted pace (GAP)?
Grade-adjusted pace is your flat-ground pace corrected for the slope you are running on. An 8:00 per mile effort on flat ground feels like about 10:00 per mile on a steady 10% climb, so GAP lets you compare hilly runs with flat runs on equal terms.
How much slower is running uphill?
As a rule of thumb used by this calculator, each 1% of uphill grade adds about 2.5% to your pace. A 5% climb turns an 8:00 mile into 9:00, and a 10% climb turns it into 10:00. Steeper climbs cost more, and the effect is an estimate, not a lab measurement.
Does running downhill make you faster?
Yes, but only modestly. This calculator gives about 1.2% faster pace per 1% of downhill grade, capped at 12% faster overall. On very steep downhills most runners slow down again because braking and footing cost energy, so the benefit does not keep growing.
Is this the same as Strava grade adjusted pace?
No. Strava grade adjusted pace is based on Minetti’s energy-cost curve for running on gradients, which gives a larger uphill penalty than the simple linear rule used here. This calculator uses a transparent linear rule so the math is easy to check, and its results should be treated as an estimate.