Distance alone will not let you compare two courses
Two half-marathon-length courses of 13.1 miles (21.1 km) are nothing alike if one climbs 650 ft (about 200 m) and the other 3,900 ft (about 1,200 m). Trail runners therefore convert total elevation gain into flat distance and add it on before comparing courses. This page takes distance, total gain and how many miles of flat you count 1,000 ft of climbing as, returns the equivalent flat distance, and shows what share of that total the climbing contributed. Changing the factor is a quick way to see how differently the same course reads.
There is no official conversion factor
How much flat distance a given climb is worth is written differently in different references and no official figure exists. The factor is therefore not hard-coded; you type it in, and the rule applied is printed back with the results so you can see which value produced them (as of October 2026). Equivalent distance is the course distance in miles plus gain in feet divided by 1,000 and multiplied by the factor. Metric references are often written as kilometers per 100 m of gain; 1 km per 100 m equals about 1.89 miles per 1,000 ft, and the metric equivalent of whatever you enter is shown under the factor box.
What this page does not do
Expected finish time and calories burned depend on fitness and weather, so they are not covered here. The page does not score a course or rate its difficulty either. Descent, surface and temperature do not enter the calculation, so two courses with the same equivalent distance can still feel different.
Frequently Asked Questions
No official figure exists, so this page does not suggest one. Use the value printed in the reference or race guide you are following and only that value is applied.
The cost of going downhill varies widely with surface and gradient, so it cannot be folded in with a single factor. This page converts total gain only.
No. Time depends on fitness and weather, so it is not covered. The page reports equivalent flat distance and the share contributed by climbing.