How to use the stopwatch
- Press Start (or Space on a computer). The time counts up to the hundredth of a second.
- Press Lap (or L) each time you pass a mark: a lap of the track, a length of the pool, a question on a practice test.
- Press Pause (or Space again) to stop the clock. Press Start to carry on from the same time.
- Press Reset (or R) to go back to zero for a new run.
Lap time vs total time
Every lap shows two numbers. The lap time is how long that one lap took, from the previous press to this one. The total is the running time since you started. Some coaches call the total a split; others use split for the lap itself. You get both here, so it doesn't matter which one you mean.
Say you run four laps of a track and press Lap at 1:52, 3:47, 5:45 and 7:38. The lap times are 1:52, 1:55, 1:58 and 1:53, and the totals are the four times on the clock when you pressed.
Your fastest and slowest lap, marked for you
Once you have a few laps, the stopwatch marks the fastest and the slowest, so you don't have to scan the list. In the example above, lap 1 is the fastest and lap 3 the slowest. For pacing, that's the useful part: a big gap between the two tells you your pace wasn't even.
When you're done, copy all laps as text and paste them into a notes app, a message to your coach or a spreadsheet.
How accurate is an online stopwatch?
This stopwatch reads your device's clock rather than counting ticks, so it doesn't drift when the browser is busy, or when you switch to another tab and the browser slows that tab down. Come back ten minutes later and the time is right.
The display goes to hundredths of a second, but in practice your thumb is the limit. The moment between seeing the finish and pressing the button is longer than a hundredth, for you and for anyone holding a stopwatch. For fair comparisons, have the same person press the button every time.
Keep the page open while you time. On a phone, the browser may pause a page you leave, so keep the stopwatch on screen for anything that matters. While it runs, the page asks the browser to keep the screen awake, on browsers that support it.
Keyboard shortcuts
On a computer, shortcuts let you keep your eyes on what you're timing. Full screen makes the numbers big enough to read across a gym or a classroom.
- Space: start or pause
- L: lap
- R: reset
- F: full screen
What to time with a stopwatch
- Running and swimming: lap times on a track or in the pool, and splits on a longer run.
- Gym: rest between sets, how long you can hold a plank, a timed circuit.
- Studying: how long each practice question takes, so you know whether you'll finish the real exam in time.
- Speaking practice: time a speech, a pitch or an interview answer, with a lap at each section to see which part runs long.
- Cooking: how long the onions took to brown, or how long the dough has been rising, when you don't know the end time in advance.
- Everyday checks: how long the commute really takes, a kid's puzzle record, a family speed challenge.
Stopwatch or timer: which one do you need?
A stopwatch counts up and you decide when to stop. A timer counts down from a length you choose and rings at zero. If you know how long something should take, like 12 minutes for cookies, use the Timer. If you want to find out how long it does take, use the stopwatch.