How to use the Lap and Split Time Calculator
Paste the cumulative readout from a stopwatch and the tool breaks it into individual lap times; switch the mode and it builds the cumulative column from per-lap times instead. It reports the number of laps, the total time, the average lap, the fastest and slowest laps, and the standard deviation that shows how uneven the laps were.
Times can be written as 1:05.30 in minutes, seconds and hundredths, as 1:02:03 with hours, or as plain seconds such as 65.3. Everything is converted to whole hundredths of a second, so the seconds field never shows 60, and a lap exactly on the average reads 0.00 sec with no minus sign. The deviation treats the laps you entered as the whole population. Current as of October 2026.
If a cumulative time is not larger than the one before it, the line number is named and the calculation stops. Target times and typical paces depend on the sport, the distance and the age group, so no comparison table is published and the math stays inside your own times. Converting a distance into a pace and predicting a finish time are not covered here.
Frequently Asked Questions
Numbers that keep growing, like the readout from a stopwatch lap button, are cumulative. Times for a single lap only are splits. Use the selector at the top to switch.
Minutes and seconds such as 1:05.30, hours, minutes and seconds such as 1:02:03, and plain seconds such as 65.3 are all read. A value of 60 or more in a minute or second field brings up a notice.
No. Standards differ by sport, distance and age group, so no comparison table is offered. Only the average and the spread of the laps you entered are calculated.