Grade-Adjusted Pace
See approximately how much uphill and downhill grades change your running pace, in seconds per mile per percent of incline.
| Grade | Pace change /mi | A 9:00/mi effort runs |
|---|---|---|
| -4% | −26 s/mi | 8:34/mi |
| -2% | −14 s/mi | 8:46/mi |
| 0% | — | 9:00/mi |
| +2% | +24 s/mi | 9:24/mi |
| +4% | +52 s/mi | 9:52/mi |
| +6% | +84 s/mi | 10:24/mi |
| +8% | +120 s/mi | 11:00/mi |
| +10% | +162 s/mi | 11:42/mi |
Approximate, for steady effort. Each 1% of incline adds roughly 12–15 s/mi uphill; downhills give back less than climbs cost.
Hills change effort: a given pace is much harder uphill and a little easier downhill. The chart shows an approximate change in seconds per mile for a range of grades, so you can keep effort steady rather than chasing flat-ground pace up a climb. As a rough rule, each 1% of incline adds on the order of 12–15 seconds per mile.
Downhills give some time back, but not as much as the climb cost, and steep descents pound your legs — so don't bank on a hilly course averaging out to flat-ground pace. To plan, take your flat goal pace from the main calculator and apply the adjustment for the steepest sustained sections.
Frequently asked questions
How much do hills slow your pace?
Roughly 12–15 seconds per mile for every 1% of incline going up; steeper grades add disproportionately more. The chart gives an estimate by grade.
Do downhills make up for uphills?
Only partly. Downhill running is faster for the same effort, but the time saved is smaller than the time a climb costs, so a rolling course usually runs slightly slower than a flat one.
What is grade-adjusted pace (GAP)?
It's your pace converted to the equivalent effort on flat ground, so you can compare hilly and flat runs fairly. Watches and apps estimate it; this page shows the approximate adjustment behind the idea.