Interval Timer and Tabata Timer
A free interval timer for Tabata, HIIT and EMOM workouts, or your own work and rest rounds, with no sign-up.
- Free
- No sign-up
- Work and rest beeps
- Full screen
Interval timer
Workout preset
Ready
Reset the workout? You're partway through.
Your intervals
Rest between sets, used when Sets is 2 or more.
Countdown before round 1.
Reset the timer to change the setup.
Sound and display
70%
Keyboard: Space to start or pause, N to skip to the next phase, R to reset, F for full screen, Esc to stop. Turn shortcuts off under Sound and display.
How to use the interval timer
- Pick a preset: Tabata 20/10, HIIT 40/20, or EMOM. Or type your own work, rest, and round counts, and the preset switches to Custom.
- For a longer session, set Sets to 2 or more and choose a Set break, the longer rest between sets.
- Press Start. The warm-up countdown gives you time to get in position, and three short beeps lead into every work interval.
- Watch or listen for the phase. Work shows in red with the word Work, rest shows in green with the word Rest, and each has its own sound.
- Use Pause if you need a break, or Skip to cut a rest short. When the last round ends you'll hear the finish sound and see Done.
- If the page reloads mid-workout, the timer picks up where the clock says you are. Tap Turn sound on to bring the beeps back.
The presets: Tabata, HIIT 40/20, and EMOM
| Preset | Work | Rest | Rounds | Total with warm-up |
|---|---|---|---|---|
| Tabata 20/10 | 20 s | 10 s | 8 | 4:00 |
| HIIT 40/20 | 40 s | 20 s | 8 | 7:50 |
| EMOM | 60 s | none | 10 | 10:10 |
Tabata (20 seconds on, 10 off, 8 rounds)
Tabata is an interval format of 20 seconds of hard work and 10 seconds of rest, repeated for 8 rounds. It is named after a 1996 study in Medicine & Science in Sports & Exercise by Tabata and colleagues, whose high-intensity group did seven to eight sets of 20 seconds of exercise with 10 seconds of rest between each bout. The study set the intensity at about 170% of each subject's VO2max (maximal oxygen uptake). The preset gives you that timing. The guide What is Tabata? covers the study and the format in more detail.
HIIT 40/20
High-intensity interval training (HIIT) is a workout style that alternates short, hard efforts with rest. It has no single fixed timing; 40 seconds of work and 20 seconds of rest is a simple one-minute cycle, and the preset runs it for 8 rounds. Treat it as a starting point and change the numbers to match the plan you're following.
EMOM (every minute on the minute)
EMOM is a workout format in which you start a set of reps at the top of every minute and rest for whatever is left of that minute. If the reps take 20 seconds, you rest 40 seconds before the next minute begins. The preset runs 60-second work rounds with no separate rest, so the work beep marks each new minute. Set Work to 120 for every 2 minutes. If every round is a plain minute with the same short rest, the one-minute round timer is a quicker way to run it.
This page times intervals. It doesn't give exercise advice, so follow the plan from your coach or program for intensity and how often to train.
How the total time is worked out
The timer lays out the whole workout before it starts: warm-up, then work and rest for each round, with the longer set break between sets. It doesn't add a rest after the last round of a set, because the set break or the end of the workout comes next.
Total = warm-up + (sets × rounds × work) + (sets × (rounds − 1) × rest) + ((sets − 1) × set break)
For the Tabata preset with 1 set: 10 s warm-up + (8 × 20 s) + (7 × 10 s) = 10 + 160 + 70 = 240 seconds, which is 4:00. The summary under the setup fields shows the total for whatever you enter, and the face counts it down as Total left while you work.
Two sets of the same Tabata with a 60-second break: 10 + (2 × 8 × 20) + (2 × 7 × 10) + (1 × 60) = 10 + 320 + 140 + 60 = 530 seconds, or 8:50.
What each sound means
Each phase change has its own sound, so you can follow the workout without looking at the screen. Press Test sounds under Sound and display to hear all four in order.
| Sound | When it plays | What you see |
|---|---|---|
| Three short ticks | 3, 2, and 1 seconds before a work interval starts (and before rest too, if you turn that on) | The phase digits counting 0:03, 0:02, 0:01 |
| Two high beeps | Work starts | Red face with the word Work |
| Two falling notes | Rest or a set break starts | Green face with the word Rest or Set break |
| Four rising notes | The last round is finished | Done, with a Stop button |
Using it with music, other tabs, or a phone
Browsers slow down page scripts in tabs you aren't looking at, so this timer doesn't count ticks. It works out where you are from the real clock, and it schedules the beeps ahead of time on the browser's audio clock. That keeps the phases on time if you switch to a music tab or another app on a computer.
Sound only works after you've pressed something on the page, which is why the beeps start with your Start press. On phones, a locked screen can pause the page and its sound, so Keep screen awake asks the browser to keep the display on during the workout, in browsers that support it. Full screen makes the phase and digits readable from across a room.
Interval timer questions
What is a Tabata timer?
A Tabata timer runs 20 seconds of work and 10 seconds of rest, repeated for 8 rounds. The timing comes from a 1996 study by Tabata and colleagues in which subjects did seven to eight 20-second bouts with 10 seconds of rest between them. Pick the Tabata preset and press Start.
Why doesn't the timer rest after the last round?
There's nothing left to rest for, so the workout ends when the last work interval does. For the Tabata preset that's 3 minutes 50 seconds of intervals, and with the 10-second warm-up the whole run is 4:00. Between sets, the Set break time takes the place of the normal rest.
What's the difference between rounds and sets?
A round is one work interval and the rest after it. A set is a full group of rounds. Two sets of 8 rounds means you do 8 rounds, take the longer Set break, then do 8 more. Leave Sets at 1 if you only want one block.
How do I set up an EMOM timer?
Pick the EMOM preset. It sets 60 seconds of work, no rest, and 10 rounds, so a new round starts with the work beep at the top of every minute. Whatever is left of the minute after you finish your reps is your rest. For every 2 minutes on the 2 minutes, change Work to 120.
Will I hear the beeps if I switch tabs or lock my phone?
In another tab, yes. The beeps are scheduled on the browser's audio clock and the timer checks the real clock, so it stays on time while you're in a music app or another tab. A locked phone is different: a phone can pause a web page and its sound when the screen turns off, so leave Keep screen awake on and the page open.
How do I share my workout setup?
Change the setup, then press Copy link to this setup. The link carries your work, rest, rounds, sets, set break, and warm-up times, so anyone who opens it gets the same intervals ready to start. Nothing is saved on a server.
Can I skip the warm-up or a rest?
Yes. Press Skip, or the N key, to jump to the start of the next phase. Skipping during the warm-up goes straight to round 1, and skipping the last work interval ends the workout.
Sources
- Tabata I. et al., "Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max," Medicine & Science in Sports & Exercise, 1996 (abstract on PubMed), pubmed.ncbi.nlm.nih.gov
- The WOD Generator, "EMOM Definition", thewodgenerator.com
- Chromium project, "Autoplay policy in Chrome" (sound needs a click or tap first), chromium.org
- Chrome for Developers, "Heavy throttling of chained JS timers beginning in Chrome 88", developer.chrome.com
- web.dev, "The Screen Wake Lock API is now supported in all browsers", web.dev
Related tools and guides
- What is Tabata?Where the 20/10 format comes from and what the study measured.
- 1 minute timerEqual one-minute rounds with a rest.
- Online timerA single countdown with an alarm, for a plank hold or a rest day stretch.
- StopwatchTime a run or a set for time, with laps.
- Time unit converterTurn seconds into minutes and back.
TimerCalculator.com's interval timer is Cedrick Reese's work. It builds the full list of phases when you press Start and reads the current phase from the real clock, so pausing, skipping, or hiding the tab can't push the rounds out of step. It was tested in an automated browser with a simulated clock. The Tabata, HIIT 40/20 and EMOM presets were loaded and their totals compared with the formula above, a two-set custom workout was run start to finish with each phase change checked against the clock, Skip was pressed to confirm it lands on the next phase, and the page was reloaded mid-workout to confirm it came back in the right round.