Swimming pace calculator
Calculate your swimming pace per 100 meters from a distance swum and a timed result, then estimate your theoretical times over other common distances (400 m, 800 m, 1500 m). Instant calculation, entirely in your browser.
How it works
In swimming, pace is traditionally measured as time per 100 meters, which makes it easy to compare sessions swum over different distances. This tool converts your time over the distance swum into a pace per 100 m, then applies that same pace to other common distances to estimate your theoretical times.
Why are predicted times rarely accurate in competition?
The prediction assumes a perfectly constant pace, which doesn't always reflect physiological reality: over a longer distance, fatigue tends to slow the pace slightly, while over a shorter distance a swimmer can go faster than their usual pace. These estimates are therefore a training benchmark rather than a guaranteed race-time prediction.
How can I use this tool to improve in training?
Regularly time yourself over the same distance (for example 400 m or 1000 m) and compare your pace per 100 m over time: a pace that gets lower week after week is a good indicator of progress. You can also use the calculated pace to set split-time targets during interval sessions.
Your times and distances stay in your browser only, with nothing sent to a server.