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Calculate swimming pace per 100m or 100yd from split times and distance. Convert between pace formats for pool and open water training plans.
Calculate critical swim speed (CSS) threshold pace from 400m and 200m time trial results. Set aerobic training zones for swimmers and triathletes.
Calculate even swimming split times for race pacing and interval training. Generate negative, even, or positive split targets for any distance.
This tool applies a standard formula from the relevant domain. The computation is deterministic — given the same inputs, the result is always identical. The formula accounts for the primary variables that determine the output.
Haversine: d = 2R × arcsin(√(sin²(Δlat/2) + cos(lat1)cos(lat2)sin²(Δlon/2)))The calculation requires: Start Latitude, Start Longitude, End Latitude, End Longitude. Each parameter contributes to the final result according to the formula above. Accuracy depends on the precision of your input measurements.
Updated: July 2026
A typical use case demonstrating the calculator with representative values.
→ Calculated result based on the formula and provided inputs
Enter your own values to get a personalized result for your specific situation.
→ Result calculated from your specific input values
Check the expected unit for each input field (shown as suffix). Converting between imperial and metric units before entering values prevents calculation errors.
Ensure denominator values (divisors) are non-zero. The calculator validates this, but understanding which fields cannot be zero helps interpret results correctly.
Calculate straight-line open water swim distance from GPS coordinates. Free online swimming calculator with instant, accurate results. It applies the calculation formula (Haversine: d = 2R × arcsin(√(sin²(Δlat/2) + cos(lat1)cos(lat2)sin²(Δlon/2)))). For example: sf bay swim segment — A typical use case demonstrating the calculator with representative values.