Swim Pace per 100m Calculator
Swim pace per 100 meters (or yards) is the standard metric for measuring swimming speed. Unlike running where pace per mile or km is common, swimmers always express pace per 100 because pool lengths are measured in 25m or 50m increments. This calculator takes your total swim time and distance to calculate your pace per 100 meters or yards. It also calculates predicted finish times at common triathlon and open water distances. Enter your time (minutes and seconds) and distance in meters to see your pace and splits.
Swim pace formula
Pace per 100m (seconds) = (total seconds) / distance(m) × 100
For a 1,500-meter swim in 25 minutes (1,500 seconds): pace = 1,500 / 1,500 x 100 = 100 seconds per 100m = 1:40/100m. To predict time at a new distance: predicted time = (pace in seconds / 100) x target distance. This assumes even pacing throughout the swim.
Common triathlon swim distances
- Sprint triathlon: 750 meters
- Olympic triathlon: 1,500 meters
- Ironman 70.3 (half): 1,900 meters
- Ironman (full): 3,800 meters
- Open water 1 mile: 1,609 meters
Swim pace calculator: frequently asked questions
What is swim pace per 100?
Swim pace per 100 (commonly written as /100m or /100y) is the time it takes to swim 100 meters or 100 yards. It is the standard unit for expressing swimming speed, equivalent to pace per mile in running. A pace of 1:30/100m means it takes 1 minute 30 seconds to swim 100 meters.
How do I calculate swim pace per 100m?
Swim pace per 100m = (total time in seconds) / (distance in meters) x 100. For example, a 1500-meter swim completed in 25 minutes (1,500 seconds): pace = 1500 / 1500 x 100 = 100 seconds per 100m = 1:40 per 100m.
What are common pool distances?
Standard competition pools are 50 meters (long course) or 25 meters (short course/yards). A 25-yard pool is the standard in the United States. One mile is 1,609 meters or approximately 64.37 lengths of a 25m pool, or 32 lengths of a 50m pool. Open water swims use metric distances (750m, 1.5km, 3.8km for triathlon).
How does pool pace compare to open water pace?
Most swimmers are 5 to 15 percent slower in open water than in a pool due to absence of lane lines (which create turbulence that assists push-off), waves, currents, wetsuit effects, sighting overhead, and turns. Wetsuit swimming can partially offset this, adding 5 to 10 percent speed in cold water due to buoyancy.
What is a good swim pace for triathlon?
For sprint triathlon (750m swim), a pace of 2:00/100m or faster is competitive. For Ironman 70.3 (1.9km swim), sub-2:00/100m is a solid goal. For full Ironman (3.8km swim), many age-groupers target 2:00 to 2:30/100m. Elite triathletes swim the Ironman leg at 1:10 to 1:20/100m.
Official sources
- World Aquatics (formerly FINA): worldaquatics.com (official swim distances and standards).
- USA Triathlon: usatriathlon.org (triathlon swim distances).
- American College of Sports Medicine: acsm.org.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.