Sprint speed calculator

It takes Distance (m) and Time (seconds) and derives Speed (m/s), Speed (km/h) and Speed (mph) from them. The calculation is live as you type, so the result updates on every change.

2 values: Distance (m) and Time (seconds). Nothing else is required — no account, no file upload.

With Distance (m) = 100 and Time (seconds) = 10, the calculator returns Speed (m/s) = 10, Speed (km/h) = 36 and Speed (mph) = 22.369. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

It moves a lot. Using Distance (m) = 110 and Time (seconds) = 20 instead, Speed (m/s) goes from 10 to 5.5 — which is why it is worth testing a few scenarios rather than trusting a single figure.

Scaled down to Distance (m) = 90 and Time (seconds) = 5, Speed (m/s) comes out at 18. The relationship is worth checking at both ends before you rely on a single result.

Preparing a race: the pace a target time needs, the splits to hold it, and the training zones that sit under it — on foot, and equally on a bike or in a pool, where the same session is measured in watts or in a hundred-metre split instead.

Scaling a time linearly to a longer distance. A marathon is not two half-marathons; race predictors use an exponent around 1.06 precisely because fatigue is not proportional.

This one returns Speed (m/s); the Cycling speed calculator returns Pace (min/km). That is the whole difference — open the one whose figure you need.

Pace Calculator is the closest one after this: Compute your running pace (min/km) and average speed from distance and time.

Swimming pace calculator and Target race pace calculator — they come up in the same task often enough to be worth a second tab.