How to Calculate Split Times in Swimming
Calculating split times in swimming is a means of calculating an individual swimmer's or relay team's pace over a series of laps. Recording splits and calculating times is useful in determining what legs of the race are covered in what amount of time. A timer can record a split after one lap -- the length of the pool; two laps -- down and back -- or any other distance he chooses. A split is the exact second that divides one lap from another. Split time is the amount of time that adds up between two splits.
Recording with Split Capable Stopwatch
Press the "reset" button or hold down the "stop" button until the stopwatch zeros out. The display on the stopwatch will read 00:00.00 when it is zeroed out. To take split times, you must zero out the watch prior to the race.
Press the "start" button when the harmonic horn sounds indicating the start of the race. For a one-lap split, press the "split" button on the top of the stopwatch when the swimmer completes his first lap.
A lap is complete when a swimmer touches the pool wall opposite that from which he began and makes a turn. If you are doing two lap splits, wait to hit the "split" button until he touches the wall on the end where he began.
Press the "split" button every time the swimmer or a member of the team completes a split distance -- every one or two laps, or every time the swimmer covers the distance you've determined marks the split. Each time you hit the "split" button, the stopwatch records the time in its memory.
Press the "stop" button once the race is complete. A race is finished when the swimmer or the last leg of a relay team completes the final lap and touches the wall.
Retrieving Splits Off Split Capable Stopwatch
Press down on the button labeled "recall" on the top of the stopwatch. Some stopwatches have a "memory" button that brings up the split times. The first split time will appear on the watch display.
Press the "recall" button a second time to retrieve the second split time, a third time for the third split and so on. When the first split time reappears on the display, you have viewed every split.
Write down each split. Write the first split at the bottom of the paper, the next split above it and so on. Leave a space between each split.
Recording Splits with Analog -- or Mechanical -- Stopwatch
Start the stopwatch when the harmonic horn sounds or starting gun fires by pressing the start button. The center top button on most analog stopwatches is the "start" button; the left button -- when the watch face is toward you -- is "reset" and the right button is "stop."
Some mechanical stop watches only have a single button. The first time you press it down, the stopwatch starts. The second time you press it, the stopwatch stops. The third time resets the stopwatch.
Watch the second hand and write down the time at which the swimmer touches the wall to make his turn. Record each split in this fashion.
Record your first split time at the bottom of the page and write the next split time above it. Leave a space in between every split in order to calculate split times.
Calculating Split Times
Subtract the second-to-last split from the last split -- when the swimmer touches the wall at the end of a race, it counts as a split. Write down the number -- the split time -- between the third-to-last split and the second-to-last.
Subtract the third-to-last split from the second-to-last split, and write the split time between the fourth and third split. Continue subtracting one split from another until you have calculated all your split times down the paper.
Subtract the second-to-last split time from the last in a separate column. Subtract the third-to-last split time from the second-to-last -- in the same separate column -- and so on. These times tell you the difference in seconds or minutes between each split time.
If you are using a mechanical stopwatch, don't forget to wind it before each race by twisting the center top knob -- the knob that also functions as the "start" button.
Do not be surprised when calculating the difference between split times if you have a negative number. Sometimes a swimmer will complete one of his last split times in faster time than he completed a beginning or middle split time.
Once you zero out a split capable stopwatch, all the split times you took are erased, so do not do so until you are finished with the split times.