About Running Calculator
Running Calculator is a collection of free tools for runners: pace, finish times, distances and splits. There is no sign-up and the calculators do not store what you enter.
What we build
Each calculator answers one clear question and shows how it got there. Formulas, assumptions and sources are written next to the tool, and every result has a link you can share.
How we check the numbers
Every calculation is covered by automated tests that include normal cases, edge cases and invalid input. Where a published table or formula exists, we check against it. You can read how each calculator works on the methodology page.
Updated October 7, 2026