20 Second Timer
Press Start and it counts down 20 seconds on a big display, then rings with the sound you pick. Space starts and pauses.
20 seconds
Alarm: Bell
Spacestart or pauseRreset+ / −a minuteFfull screenMmute
Sound and moreBell
A different length
How this works: 2 sources, Checked against 1 worked example,
How this works
Sources
How it’s tested
One worked example for this page is checked by automated tests before every release: given the inputs, the tool must show the expected answer.
Changes
- Added 10, 20, 30, 45 and 90 second timer pages, each with its own uses, a table and cited facts.
- A timer opened from a link no longer resets on reload, a tap brings the sound back after one, and on phones Start is on the first screen.
- First published.
Twenty seconds, for clean hands and hard rounds
The most useful twenty seconds of the day happens at the sink. The CDC asks for at least 20 seconds of scrubbing with soap, covering the backs of your hands, between your fingers and under your nails, which is longer than most people manage when they guess. Its own trick is to hum Happy Birthday from beginning to end twice; a phone propped by the sink with this timer is a quieter way, and children often like racing the countdown to the bell.
In training, twenty seconds is the work interval of the Tabata protocol: twenty seconds as hard as you can, ten seconds of rest, repeated. In the original 1996 study, volunteers rode an exercise bike for seven or eight of these sets, five days a week for six weeks. Eight rounds of twenty plus ten make the familiar four-minute block. This page times one work interval at a time; for the whole on-off sequence with beeps, the interval timer repeats it for you, and the table shows how long longer blocks take.
- The CDC recommends scrubbing your hands with soap for at least 20 seconds, and suggests humming “Happy Birthday” twice to time it. Source: CDC, About Clean Hands: how to wash your hands.
- The original Tabata training was seven to eight sets of 20 seconds of exercise at about 170% of VO2max, with 10 seconds of rest between bouts, on a cycle ergometer. Source: Tabata et al., Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max (Med Sci Sports Exerc, 1996).
Tabata-style rounds of 20 seconds on, 10 seconds off
Total time for each number of rounds, counting the rest after the last one, as the classic 8-round, 4-minute block does.
| Rounds | Work | Rest | Total (m:ss) |
|---|---|---|---|
| 2 | 40 seconds | 20 seconds | 1:00 |
| 4 | 1 min 20 s | 40 seconds | 2:00 |
| 6 | 2 minutes | 1 minute | 3:00 |
| 8 | 2 min 40 s | 1 min 20 s | 4:00 |
| 10 | 3 min 20 s | 1 min 40 s | 5:00 |
| 12 | 4 minutes | 2 minutes | 6:00 |
| 16 | 5 min 20 s | 2 min 40 s | 8:00 |
| 20 | 6 min 40 s | 3 min 20 s | 10:00 |
| 24 | 8 minutes | 4 minutes | 12:00 |
| 32 | 10 min 40 s | 5 min 20 s | 16:00 |
20 seconds in other units
| Unit | Value |
|---|---|
| Milliseconds | 20,000 |
| Minutes | 0.3333 |
| Share of an hour | 0.556% |
| Times it fits in an hour | 180 |
| Times it fits in a day | 4,320 |
Frequently Asked Questions
Why wash your hands for 20 seconds?
It is the CDC’s guidance: at least 20 seconds of scrubbing with soap, so the lather reaches every part of both hands. Rinse under clean running water afterwards and dry them with a clean towel or let them air dry. Start this timer when you begin scrubbing, not when you turn on the tap.
What is a Tabata workout?
Rounds of 20 seconds of very hard effort followed by 10 seconds of rest, usually eight rounds, four minutes in all. It comes from a 1996 study by Izumi Tabata and colleagues on an exercise bike. Build up to it if you are new to hard exercise, and check with a doctor first if you have a heart condition.
Can this timer repeat 20 seconds on and 10 off by itself?
Not this page: it counts one 20-second stretch and rings. Press Space to start the next one. For rounds that run on their own, with a beep between work and rest, use the interval timer, which has a Tabata preset.