Tumble Turn Time Saving Calculator

How it is calculated

You supply the time one touch turn takes, the time one tumble (flip) turn takes, both in seconds, and the number of turns in the swim. The tool takes the difference per turn and scales it: per-turn saving = touch time − tumble time and total saving = per-turn saving × number of turns. Both times are positive numbers of seconds (up to 600) measured the same way, for example from the moment the head reaches a mark before the wall until it passes the same mark after the push-off. The number of turns must be a whole number above zero. The results are shown in seconds to two decimals. If the tumble turn is slower than the touch turn, the saving comes out negative and is labelled "slower than a touch turn" rather than shown as an error; zero or negative times, or a fractional turn count, show no result. The tool does not account for fatigue, underwater distance rules or turn technique changing across a race.

Common mistakes

• Counting lengths instead of turns. A swim of n lengths has n − 1 turns, because the start and the final touch are not turns, so 16 lengths means 15 turns.
• Timing the two turn types over different distances. The comparison only works if both times cover the same stretch before and after the wall, for example 5 m in and 5 m out.
• Entering the time of the whole length instead of the turn. The inputs are the turn times, a second or two, not the lap time; anything above 600 seconds is rejected.
• Swapping the two time fields. The answer then turns negative (-10.95 sec) and is flagged as slower than a touch turn.
• Using the result as a prediction for a final race time. Both times come from fresh-legged practice measurements, and fatigue usually makes late turns slower.