How to Use an Online Stopwatch (With Laps)

Reading the display

The time is shown as minutes:seconds.centiseconds — so 02:34.50 means 2 minutes, 34 seconds and 50 hundredths of a second. Centiseconds are the two small digits after the dot; 100 of them make one second.

Start, pause and resume

Press Start to begin timing. Press Pause to freeze the display — the clock remembers where it stopped, so pressing Start again resumes from the same time rather than starting over. Reset clears everything back to zero.

What laps are for

The Lap button records the current time without stopping the clock. Use it to mark each segment of an activity: each length of a swim, each lap of a track, each question in a practice exam.

Laps are listed newest first, so the most recent lap is always at the top. The newest entry is Lap 1 of the current viewing order, with earlier laps numbered below it.

Worked example

Timing a 4-lap run: press Start as you begin, press Lap at the end of each circuit. If the laps read 01:32.40, 03:05.10, 04:41.80 and 06:15.20, your first lap took 1:32.4 and your second took about 1:32.7 (03:05.10 minus 01:32.40).

Tips for accurate timing

A few things worth knowing:

• The stopwatch runs entirely in your browser — closing the tab loses the time
• Keep the tab visible; some browsers slow background tabs
• For anything under a minute, watch the centiseconds — they show how consistent your laps really are