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Cardio As of 2026-04-24

How Swim Pace Calculator works

Methodology for the Swim Pace Calculator: formulas, coefficients, data sources, assumptions, and known limitations.

Scope

Calculates swim pace, total time, or distance for any two of the three, with SWOLF and effort context.

Formula

pace_per_100 = total_time / distance * 100. SWOLF = stroke_count + seconds per length.

Coefficients

Parameter Value Note
Pool length options 25 m, 50 m, 25 yd

Data sources

  1. World Aquatics (formerly FINA) — Facilities Rules: pool dimensions and timing standards. — Federation specification for 25 m, 50 m, and short-course pool lengths and competition timing.
  2. USA Swimming — Rules and Regulations: course-length and timing standards. — U.S. governing body for swimming course measurement and meet-time standards.

Assumptions

  • Pool length is accurate; open-water GPS adds substantial noise.

Approximation range

Arithmetic is exact; SWOLF trends reflect stroke efficiency over sessions.

Limitations

  • Pace does not capture stroke type, open-water conditions, or currents.

Reproducibility

1000 m in 18:00. Pace = 18*60/10 = 108 s/100 m = 1:48/100 m.

Change log

  • 2026-04-24: methodology page first published.
General fitness estimates — not medical advice. Consult a healthcare professional for medical decisions.