Elevation Gain Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/5/2026
A course's average slope is found by dividing the elevation gain by the distance (in meters), multiplied by 100. Example: 500 m of elevation gain over 10 km gives an average slope of 5%.
Explanation
Two courses of the same distance can demand very different effort depending on their elevation gain: comparing only the kilometers covered underestimates the difficulty of a mountainous course. This calculator gives two complementary indicators. Average slope (%) is a simple geometric calculation: elevation gain relative to the horizontal distance covered — useful for comparing the steepness of two courses. Effort-distance applies a common convention among trail runners: 100 m of elevation gain roughly equals 1 extra km of effort on flat terrain. This is an empirical rule of thumb, not a universal physical law — actual effort also depends on the exact steepness of the slope, the terrain (technical trail or wide path), and the runner's fitness. For the pace achieved on a hilly course, see our running pace calculator.
Example: a 10 km trail with 500 m of elevation gain
Inputs
Distance: 10 km. Elevation gain: 500 m.
Calculation
Average slope = (500 ÷ (10 × 1,000)) × 100 = (500 ÷ 10,000) × 100 = 5%. Effort-distance = 10 + (500 ÷ 100) = 10 + 5 = 15 effort-km.
Result
Average slope: 5%. Equivalent effort-distance: about 15 km.
Frequently asked questions
Is the "100 m of gain = 1 km of effort" convention an official rule?
No, it's a widely used convention among trail runners and some race organizers for estimating comparable difficulty between courses, not a universally validated physical formula. It gives a useful ballpark figure, not an exact measure of effort, which also depends on the actual steepness of the slope and the terrain.
Why isn't average slope enough to judge a course?
Because it smooths out irregularities: a course with a 5% average slope might alternate long flat stretches with a very steep climb, which is far more demanding than a steady 5% slope from start to finish, even though the average slope would be identical in both cases.
Does downhill elevation count in this calculation?
No, this calculator only accounts for elevation gain (climbing), which is generally the limiting factor for cardiovascular effort. Elevation loss (descending) stresses the body differently (muscular impact rather than cardio effort) and isn't covered by this convention.