Guide

How swim time conversion works

A conversion formula estimates how a swim may translate between pool courses. It is a planning tool—not a substitute for an official time, a sanctioned table, or the swimmer’s real performance.

Quick answer

SwimTimeCalculator.com offers two estimates. The classical method uses public course factors and stroke-sensitive sprint adjustments. The wall-adjusted method estimates speed between the walls, then changes the number of wall opportunities for the target course.

The classical model

For common sprint events, a yards-to-meters baseline is combined with an estimated turn adjustment. Distance-event pairings use separate factors.

estimated target time = source time × course factor + turn adjustment

The inverse calculation removes the adjustment and divides by the relevant factor. Calculations are performed in hundredths to keep displayed times stable.

The wall-adjusted model

This optional model first adds back a small estimated benefit for each source-course wall. It derives a free-water pace, maps the event to the target distance, and then applies the target course’s wall count.

free-water time ≈ race time + (walls × estimated wall gain)

Why two swimmers convert differently

Turn speed, underwater distance, kick strength, stroke efficiency, start quality, and fatigue all matter. Published research and coaching analysis consistently show that wall performance is an important source of variation between short- and long-course results.

What the converter does not do

For the full version history and source notes, see the methodology page.