Explanation
Outside of high school, swimming is a year-round sport. During the winter, we swim what is called the “Short Course” season, with pools 25 yards (or 25 meters) in length. Summer is the “Long Course” season, and meets are held at pools 50 meters in length. This calculator is designed to help convert between Long Course and Short Course times, or simply between meters and yards.
The swim time calculator is based on a meter-to-yard conversion factor of 1.11. It also includes a turn factor for the various strokes in “seconds per turn” as listed below. The turn factor is added or subtracted based on the course length.
- Butterfly: .7 sec/turn
- Backstroke: .6 sec/turn
- Breaststroke: 1 sec/turn
- Freestyle: .8 sec/turn
- I.M.: .8 sec/turn
Note that these are “rule of thumb” numbers for estimating only, based on swimmers with excellent technique! Lets take, for instance, 100m to 100yd butterfly conversion:
sc_time = ( lc_time - ( 2 * .7 )) / 1.11
To estimate an equivalent Short Course time, we first subtract the turn factor (2 * .7/turn for butterfly). The reason is that there are two fewer turns in the 100m Long Course compared to a 100yd Short Course. Next we convert the Long Course time to decimal minutes, then divide the result by the meter to yard factor. Here's the arithmetic:
First subtract the "turns" factor: 1 min 6 sec - (2 * .7) = 1 min 4.6 sec Convert to decimal minutes: 1 min + (4.6/60) = 1.0767 min sc_time = 1.0767 / 1.11 = .97 min .97 min * 60 = 58.19 sec
Wow, that's fast!