Work out your running pace (min/km), speed and splits from a distance and finish time locally - no upload, in your browser.
| Distance | Time |
|---|---|
| 1 km | 5:00 |
| 5 km | 25:00 |
| 10 km | 50:00 |
| 21.1 km | 1:45:29 |
| 42.2 km | 3:30:59 |
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Pace is your running speed expressed as a time per kilometre (for example 5:00 min/km). It is the figure runners plan with: from a distance and a target finish time you get the pace you need, and conversely the pace predicts how long a route will take. This calculator takes your distance in kilometres and your time in hours, minutes and seconds and shows the pace per kilometre, the speed in km/h and the pace per mile. Plus a table of split times at the classic distances of 1 km, 5 km, 10 km, half marathon and marathon.
The calculation runs entirely locally in your browser, in pure JavaScript - nothing is uploaded and nothing is stored. The pace is your total time in seconds divided by the distance, shown as minutes and seconds. The speed is the distance divided by the time in hours. The pace per mile converts the pace per kilometre with the factor 1.609344. The splits assume your pace times each distance at a constant tempo. Change an input and the result and table update instantly.
An honest note: the splits assume an even tempo over the whole route. In reality pace varies with hills, wind, surface and fatigue, and a marathon is rarely run at exactly 10 km pace. The calculator is a plain conversion of distance and time, not a training plan or sports-medicine advice. Use it to plan target times and to compare runs.
| Input formats | Form inputs (no file) |
|---|---|
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: A plain conversion of distance and time; the splits assume an even tempo. Real runs vary with hills, wind, surface and fatigue. Pace per mile uses the factor 1.609344. Not a training plan or sports-medicine advice.
No. The calculation runs entirely locally in the browser (pure JavaScript); nothing is sent or stored.
Pace is the time per kilometre, for example 5:00 min/km. It is the inverse of speed and the usual measure in running.
Your pace per kilometre times each distance, at a constant tempo. Real runs differ because of hills, wind and fatigue.
Input is in kilometres; the result additionally shows the pace per mile (factor 1.609344).