Stopwatch
Press Start to count up from zero, press Lap to record a split without stopping the clock, and press Pause to hold the time. Every lap is listed with its own time and the running total. Use it for timed reading, presentations, experiments and training. Free, no sign-up.
00:00.00
minutes : seconds . hundredths
How to Use the Stopwatch
- 1. Press Start. The display counts up in minutes, seconds and hundredths of a second (mm:ss.cc), and adds an hours column after 60 minutes (h:mm:ss.cc).
- 2. Record laps as you go. Press Lap while the clock is running. It is switched off while paused. Each lap is added to a table showing the lap number, the time since the previous lap, and the total time so far, with the newest at the top.
- 3. Pause and resume. Pause holds the time, and the button then reads Resume; press it to carry on from where you stopped.
- 4. Reset. Reset clears the clock and every lap. It is greyed out while the clock reads zero.
Lap Time and Total Time
The two columns answer different questions. The total time (often called the split) is the clock reading at the moment you pressed Lap. The lap time is how long that stretch took on its own: this lap's total minus the previous lap's total. The first lap's lap time equals its total.
Example: three laps on a reading task
Lap 1
Total 01:05.20, so lap time 01:05.20
Lap 2
Total 02:08.75, so lap time 02:08.75 − 01:05.20 = 01:03.55
Lap 3
Total 03:14.10, so lap time 03:14.10 − 02:08.75 = 01:05.35
The table does not highlight your fastest or slowest lap or let you export it, so copy the numbers down if you need them later. They are lost when you reset or leave the page.
Timing Your Own Reading Speed
A stopwatch is all you need to measure how fast you read on paper. Count the words in the passage, start the clock when you begin and stop it when you finish, then divide: words per minute = words ÷ minutes. A 600-word passage read in 2:30.00 is 2.5 minutes, so 600 ÷ 2.5 = 240 words per minute. For comparison, Marc Brysbaert's 2019 review of 190 studies put the average adult silent reading rate in English at about 238 words per minute for non-fiction and 260 for fiction. If you would rather read on screen and have the page do the timing, use the Reading Speed Test.
How Precise Is It?
The display shows hundredths of a second, and it reads your device's clock every time it refreshes rather than counting ticks, so it does not drift if the browser is busy or the tab is in the background. The hundredths are display resolution, not a promise of that accuracy in your result: the biggest error in hand timing is the delay between an event and your finger pressing the button, which is usually a fraction of a second. For comparisons, use the same method every time. For official results at a sporting event, use the organiser's timing.
Which Tool Do You Need?
| If you want… | Use |
|---|---|
| To count up from zero and record laps | This Stopwatch |
| To count down from a set time to an alarm | Countdown Timer |
| Work and break phases that repeat on their own | Pomodoro Timer |
| Your reading speed measured on screen with a comprehension check | Reading Speed Test |
| A typing speed score in words per minute | Typing Speed Test |
Frequently Asked Questions
- How accurate is this online stopwatch?
- The elapsed time is calculated from your device's clock on every refresh, so it does not fall behind if the browser slows down or the tab is hidden. It is displayed to 0.01 second. Your own reaction time when starting and stopping is a larger source of error than the software.
- What is the difference between lap time and total time?
- Total time is the clock reading when you pressed Lap, measured from the start. Lap time is the time since the previous lap, or since the start for the first lap. If your total times are 1:05.20 and 2:08.75, the second lap time is 1:03.55.
- Does it keep running if I switch tabs?
- Yes. Because the time comes from the clock rather than a count of ticks, switching tabs or minimising the window does not change the result, and the elapsed time also appears in the tab title. Reloading or closing the page does stop and clear it.
- What happens after one hour?
- The display adds an hours column, so 75 minutes is shown as 1:15:00.00 and the units line under the clock changes to hours, minutes, seconds and hundredths. There is no upper limit you are likely to meet.
- Can I save or export my laps?
- No. The laps appear on the page only, in a table you can select and copy. They are not stored, so they are cleared by Reset and lost when you leave the page.
- Does my time leave my browser?
- No. The stopwatch runs entirely in your browser and nothing is stored or uploaded.