Pool Length Conversion Calculator

About this calculator

Swim times don't scale linearly between short-course (25-yard or 25-meter) and long-course (50-meter) pools because every wall turn provides a push-off that a swimmer doesn't get mid-length, so a pool with more turns per given distance produces faster raw times for the same swimmer and effort. Converting a time from one course length to another uses a 'turn value' — an empirically derived time credit per turn, specific to stroke and distance — added or subtracted based on how many additional or fewer turns the target course length involves.

Swimmers and coaches use pool-length conversion to compare a short-course-yards time from a dual meet against a long-course-meters time from a summer championship, to set realistic goal times when moving between training pools of different lengths, and to submit times for ranking systems that require a specific course length. Standard conversion factors, like those published by USA Swimming, are the reference most conversions are built from.

This calculator takes your swim time, stroke, distance and current pool length, and returns your converted time for the target pool length using the turn-value method.