Work out swim stroke rate instantly with clear inputs, formula shown and shareable results.
Stroke rate is strokes per minute, and multiplying it by distance per stroke gives swimming speed. 30 strokes in 45 seconds is 40 a minute, so at 1.2 m/s each stroke covers 1.8 m. The stroke index - speed times distance per stroke - is the standard efficiency metric, and rises as technique improves.
Stroke rate
rate = strokes / seconds x 60
Stroke index
index = speed x distance per stroke
This is an estimate from population-average equations, not a medical or diagnostic assessment. Individual results vary with genetics, training history and technique. Seek advice from a qualified coach or clinician before making significant changes to training.
Not on its own. Sprinters use high rates, distance swimmers trade rate for distance per stroke. The product is what determines speed.
Efficiency. For a given speed, a swimmer covering more distance per stroke is wasting less energy on drag and slippage.