GAP Calculator — Grade Adjusted Pace
Convert between hilly and flat-equivalent pace. Enter your distance, time and elevation gain to find your grade adjusted pace (GAP).
Trail and hill running gear
Hill running rewards good trail shoes and a watch that can track grade and elevation accurately.
Salomon Speedcross
Deep lug pattern grips technical trails and muddy inclines. A trusted choice for off-road runners.
View on AmazonGarmin Fenix 7
Calculates grade adjusted pace automatically and provides detailed elevation profiles for every run.
View on AmazonCompression Socks
Reduce calf fatigue on hilly courses and aid recovery after long climbs.
View on AmazonHow it works
GAP uses the Minetti et al. energy cost model for gradient running. The formula accounts for the exponentially increasing cost of running uphill versus the modest recovery benefit of downhill running. This gives a flat-equivalent effort you can compare to your road training zones.
Frequently asked questions
What is Grade Adjusted Pace?
GAP converts your hilly running pace into an equivalent flat-ground effort. Running up a 5% gradient requires significantly more energy than flat running — GAP lets you compare hill workouts fairly with flat runs and use consistent training zones.
How much slower do hills make you?
A 5% grade adds roughly 25–30 seconds per km to your effective effort. A 10% grade can add 60–90 seconds. The relationship is non-linear — steeper grades carry a disproportionately higher energy cost.
Should I use GAP for all my runs?
GAP is most useful when training on hilly routes and wanting to hit specific effort targets. For flat road running, pace zones are sufficient. Most modern GPS watches calculate GAP automatically.