Stopwatch
Free online stopwatch with lap times. Accurate millisecond timer for sports, cooking, and timing events.
00:00.000
About this calculator
A free online stopwatch with lap times. Start, record laps and reset, with hundredths or thousandths of a second shown.
Use it for sport, cooking, study sessions and experiments.
How to use it
- Press Start.
- Press Lap to record a split.
- Press Reset to clear.
Laps and splits
The stopwatch measures elapsed time from the system clock, so it stays accurate even if the page is momentarily slow. Lap records the split since the previous lap without stopping the clock, and the total keeps running. Display format is mm:ss.ms; 1:05.250 means 1 minute 5.25 seconds.
Worked example
Examples
| Lap 1 | 0:32.40 |
| Lap 2 | 0:31.90 (split) |
| Total | 1:04.30 |
Tips and common mistakes
- Practise hitting Start and Stop with the same finger.
- Browser timing is accurate to a few milliseconds, not hardware precise.
- Use laps for interval training.
- Keep the tab active.
- Write down times before resetting.
Frequently asked questions
How accurate is it?
Within a few milliseconds.
What is a lap?
A split time since the last lap.
Does it run in a background tab?
The clock keeps time but keep the page open.
Can I save the laps?
Copy or screenshot them.
Is it free?
Yes.
Can I time hours?
Yes.