Swim Pace per 100 Meters: Converting Pace to Race Times for Pool and Open Water
October 29, 2026
Swimmers measure speed as time per 100 meters (or per 100 yards in US pools), not in miles per hour. To estimate a race time, multiply the pace per 100 m by the distance in hundreds of meters. At 2:00 per 100 m, a 400 m swim takes 8:00, a 1,500 m swim takes 30:00, and the 3.8 km Ironman swim takes 76:00 (1 hour 16 minutes), assuming a steady pace.
Yard pools are common in the United States: 100 yards is 91.44 meters, so a 1:40 per 100 yards pace equals 1:49 per 100 meters. Always check which unit you are using.
Skip the math and get your answer instantly:
Open the Speed Calculator →Pace and Race-Time Table
The table lists times for common distances at several paces per 100 m. A 1,500 m time at 1:30 per 100 m is 22:30, a good result for a competitive age-group swimmer. Typical recreational lap swimmers fall between 2:00 and 2:30 per 100 m.
| Pace per 100 m | 400 m | 1,500 m | 1 mile (1,609 m) | 3.8 km (Ironman) |
|---|---|---|---|---|
| 1:30 | 6:00 | 22:30 | 24:09 | 57:00 |
| 1:45 | 7:00 | 26:15 | 28:09 | 1:06:30 |
| 2:00 | 8:00 | 30:00 | 32:11 | 1:16:00 |
| 2:15 | 9:00 | 33:45 | 36:13 | 1:25:30 |
| 2:30 | 10:00 | 37:30 | 40:14 | 1:35:00 |
Pool vs. Open Water
Open-water swimming is usually slower than pool swimming at the same effort. There are no walls to push off (a push-off saves roughly 1 to 2 seconds per length), and you must sight the course, deal with chop, currents, crowding, and cold water. A swimmer at 1:45 per 100 m in the pool might swim 1:55 to 2:05 in open water, a 10% to 15% slowdown. A wetsuit can improve pace by 3% to 8% through buoyancy and body position, particularly for weaker swimmers. Swimming off course by even 5% adds 5% to the distance. Race times in open water should be estimated with these adjustments.
Setting Training Paces
A common benchmark is the critical swim speed (CSS), calculated from two time trials. Swim 400 m and 200 m with full recovery; suppose the times are 6:40 (400 s) and 3:08 (188 s). CSS pace per 100 m = (400 − 188) ÷ (400 − 200) × 100 = 106 seconds, or 1:46 per 100 m. This approximates the pace you can sustain for about 20 to 30 minutes and is a good base for training intervals: for example, 10 × 100 m at CSS pace with 15 seconds of rest, or 5 × 400 m at CSS plus 3 seconds per 100.
Repeat the test every 6 to 8 weeks to monitor improvement.
Stroke Efficiency
Pace is the product of stroke rate and distance per stroke. Many swimmers improve by increasing distance per stroke (through better technique, a longer glide, and a stronger catch) before increasing stroke rate. SWOLF, the sum of time and strokes per length, is a useful efficiency measure: a 25 m length in 20 seconds with 16 strokes gives a SWOLF of 36. Lower is better, for a given pace. Technique coaching and drills usually give faster gains than adding yardage.
Frequently Asked Questions
How do I convert swim pace to race time?
Multiply the pace per 100 m by the distance in hundreds of meters.
What is a good 100 m swim pace?
Recreational swimmers are often 2:00 to 2:30 per 100 m, and competitive swimmers 1:20 or faster.
Why is open water slower?
No wall push-offs, plus sighting, chop, and crowds.
What is critical swim speed?
The pace you can sustain for roughly 20 to 30 minutes, estimated from 200 m and 400 m time trials.
How do I convert yards to meters?
Multiply yards by 0.9144.