Use this free online stopwatch to time anything precisely — workouts, cooking, presentations, or games — with start, pause, reset, and lap tracking, right in your browser.
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How to Use the Stopwatch
Click "Start" to begin timing.
Click "Lap" at any point to record a split time without stopping the clock.
Click "Pause" to stop timing, or "Reset" to clear everything and start over.
How the Stopwatch Keeps Time
When you press Start, the stopwatch notes the exact moment from your device clock. About a hundred times a second it works out the elapsed time as "now minus the start moment", plus any time already banked before a pause. Because it measures the gap between two clock readings rather than counting ticks, the total does not drift if the browser is slow to refresh the display.
The display shows minutes, seconds and hundredths (MM:SS.cc). Once an hour has passed it switches to HH:MM:SS.cc. Digits are cut off, not rounded, so 12.348 seconds shows as 00:12.34.
Reading Lap Times: Split vs Lap Duration
Each lap entry records the total time on the clock when you pressed Lap, measured from the original start. This is often called a split time. To find how long an individual lap took, subtract the previous entry. For example, a runner doing three rounds of a track:
Lap
Time shown (split)
Duration of that lap
1
01:52.30
1:52.30
2
03:47.10
1:54.80
3
05:40.85
1:53.75
Here the second lap was the slowest. The list on screen shows the newest lap at the top, while the copied or shared text lists laps in order from Lap 1.
Good to Know Before You Rely on It
Pause keeps the time and lets you resume with Start. Reset clears both the time and all laps, and cannot be undone.
Laps can only be recorded while the clock is running.
Refreshing the page or opening another calculator in the same tab stops the stopwatch and clears it. Keep it in its own tab for long sessions.
Your reaction time when clicking is usually a bigger source of error than the clock itself, often a tenth of a second or more. Hand timing is fine for practice, study sessions or cooking, but not for official race results.
If your device clock is changed while timing, for example by an automatic time sync, the reading can jump. This is rare but worth knowing for very long sessions.
Frequently Asked Questions
It tracks time to the hundredth of a second (centiseconds) using your device clock, which is accurate enough for everyday timing needs like workouts or cooking.
Yes, click "Lap" as many times as you need while the stopwatch is running — every lap time is recorded and listed, most recent first.
Yes. Browsers may slow down screen updates in background tabs, but the elapsed time is calculated from the clock, so the correct time appears as soon as you return. Closing or refreshing the tab, however, clears it.
From the start. Each lap shows the total running time when you pressed Lap. Subtract the previous lap from it to get the time taken for that lap alone.
Pause freezes the clock and keeps your laps, and pressing Start continues from the same time. Reset stops the clock, sets it back to zero and deletes every recorded lap.