Open Water Swim Time Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Enter details
Distance(m)
Pace per 100 m
:
Result
Fill in the fields to see your result.
Estimate only — real results depend on terrain, weather, fatigue, conditions and individual fitness. Not medical or coaching advice.
How to use this calculator
- Enter the distance (m) and your expected open-water pace per 100 m.
- Read the estimated time.
How it works
Time = (distance ÷ 100) × pace per 100 m. Use a realistic open-water pace, not your pool pace.
Worked example
1900 m @ 2:00/100 m. = 38:00.
Tips
- Times are estimates only — not medical or coaching advice. Always train safely and follow event rules.
- Distances are editable: choose “Custom…” to enter your own course lengths.
Frequently asked questions
Why is open water slower?
Chop, sighting, current, temperature and wetsuit drag all add time versus a pool.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.