Plan your race pace from a recent run

The job

Enter the distance and the elapsed time; the tool returns pace per kilometer, pace per mile, and speed in both units. Works for any distance — a 400m repeat or a marathon.

Using the number

Pace is more actionable than speed for racing: 'run 5:12/km' translates directly to split targets on a marked course. Check your watch at each kilometer marker against the plan.

For interval sessions, run the repeats through separately — a set of 400s at 90 seconds each is 3:45/km pace.

Reality check

This is flat arithmetic: it divides distance by time. A hilly course, heat, or a slow first kilometer all change what pace is realistic — the number describes what happened, not what will.