Grade Adjusted Pace Calculator
Running uphill costs more energy than running on the flat, and running downhill costs less (up to a point). Grade adjusted pace converts your actual pace on a slope to the flat-ground pace that would require the same metabolic effort, so you can compare hilly and flat efforts fairly. This calculator uses the Minetti et al. polynomial for the energy cost of gradient running. Enter your pace and the gradient to see your equivalent flat pace.
Grade adjusted pace formula
i = grade / 100 (as a fraction)
C(i) = 155.4 i^5 - 30.4 i^4 - 43.3 i^3 + 46.3 i^2 + 19.5 i + 3.6
factor = C(i) / C(0), where C(0) = 3.6
GAP = actual pace / factor
C(i) is the metabolic cost of running per kilogram per metre at gradient i, from Minetti et al. (2002). Dividing by the flat cost of 3.6 gives a multiplier; a higher cost on a climb means your equivalent flat pace is faster than your actual pace.
Worked example
Running at 300 sec/km up a 5 percent grade: i = 0.05. C(0.05) = approximately 4.685. Factor = 4.685 / 3.6 = 1.301. GAP = 300 / 1.301 = 230.51 sec/km, meaning that uphill effort equals a much faster flat pace.
Frequently asked questions
What is grade adjusted pace?
Grade adjusted pace (GAP) is the flat-ground running pace that would require the same energy as your actual pace on a hill. It lets you compare the effort of hilly and flat runs on a common scale.
Which model does this use?
It uses the Minetti et al. (2002) polynomial for the energy cost of gradient running, a peer-reviewed equation widely used for grade adjustment. The flat cost reference is 3.6 J per kg per metre.
Is downhill always easier?
Down to roughly a 10 to 15 percent decline, the energy cost falls below flat running, so downhill is easier. On steeper descents braking forces raise the cost again, which the Minetti polynomial captures.
Sources
- U.S. National Library of Medicine (PubMed): Minetti et al. 2002, energy cost of walking and running at extreme slopes.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.