Swim Pace Calculator | Pace per 100m & Split Conversions

Enter your swim distance and time to get pace per 100m, speed in km/h and m/s, and even-pace splits from 50m up to 1500m. A simple way to compare any swim against the standard 100m benchmark.

💡 About this tool

"I swam 400m in 6 minutes — is that fast?" Comparing swims across different distances is awkward, because the raw time depends on how far you went. This calculator converts your distance and time into pace per 100m, the reference unit coaches and triathletes use. Once everything is on a per-100m basis, a 25m pool set and a long open-water swim sit on the same scale.

It also shows what each distance would take if you held that exact pace, laid out in a split table. Distance presets cover 25m, 50m, 100m, 200m, 400m, 800m and 1500m, and you can type any custom distance. It is handy when you are setting a workout target or working backwards from a goal time.

🧐 Frequently Asked Questions

How is pace per 100m calculated? Time in seconds is divided by distance in meters, then multiplied by 100. Swim 400m in 6 minutes (360s) and you get 360 ÷ 400 × 100 = 90 seconds, or 1:30 per 100m.

Are the split times real race predictions? No. They assume you hold the entered pace evenly from start to finish. In a real race, pace usually slows over longer distances, so treat the splits as an even-pace reference rather than a forecast.

What is the difference between a split and a lap? A split is the cumulative time from the start to a given point; a lap is the time for one segment. The table here shows cumulative times (splits) to each distance.

Does it handle yards? Yes. Use the meters/yards toggle at the top to switch units; the presets, pace per 100, and split table all update to yards (yd) for yard-pool distances like 25yd and 50yd.

📚 Even pacing vs. negative splits

Holding a steady pace is the simplest way to swim a distance event, and it is exactly what this calculator models. Many distance swimmers, however, aim for a negative split — covering the second half faster than the first to conserve energy early and finish strong. Because the tool gives you the even-pace number, it makes a useful baseline: pick a 100m pace you can sustain across the whole distance, confirm the splits look realistic, then decide whether to ease off the opening laps and build speed toward the wall.