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Timer

0:10

10 rounds · 30s work / 15s rest

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Rounds

My times

  • Nothing saved yet. Saved times stay on this device — no account, nothing uploaded.

My sequences

A routine of named steps, each with its own length, run in order and repeated.

    New sequence

      An audio file up to 1 MB. It stays in this browser and appears as "My sound" in the Sound list.

      Space
      Start or pause
      F
      Fullscreen
      Esc
      Leave fullscreen
      R
      Reset
      ↑
      Add a minute
      ↓
      Take off a minute
      M
      Mute or unmute

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      Read next: What is an EMOM workout? How it works, and how to set one upAll 8 timers

      HIIT timer for 30/15 and 40/20 intervals

      The work-to-rest ratio is the whole design of a HIIT session. One to one lets you repeat the effort; two to one does not, and that is the point of it rather than a flaw.

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      The short answer

      Two common structures cover most HIIT sessions: 30 seconds of work to 15 of rest for a two-to-one ratio you can sustain across many rounds, and 40/20 for a harder version of the same shape. If you cannot hold the same output in the last round as the first, the rest is too short for the effort you are putting in — lengthen the rest before you shorten the work.

      How to use it

      Three steps to a timer on the wall

      1. Step 1: Choose a time

        Pick a preset or set your own. The timer remembers what you used last on this device.

      2. Step 2: Press start

        Start the timer, then press F or the fullscreen button to fill the screen.

      3. Step 3: Run the room

        Space pauses, the up arrow adds a minute, R resets. Fullscreen shows the timer alone, with no ads and no navigation.

      Running it well

      Four things worth knowing

      • Pick the ratio for the intensity, not the other way round

        Near-maximum efforts need one-to-two work to rest. Sustainable efforts work at two-to-one. Choosing 45/15 and then going easy produces a long warm-up rather than a HIIT session.

      • Judge it on the last round

        If round eight looks nothing like round one, the session was mis-set. Lengthening the rest keeps the quality up and is more useful than adding rounds.

      • Count the transition in the rest

        Moving between stations eats the rest. Where a session involves changing position or equipment, use 20 seconds rather than 15 so the rest is actually rest.

      • Set it up before you start moving

        Press F for fullscreen and put the phone or the gym TV where you can see the colour. The colour tells you the phase without you having to read a number while breathing hard.

      In the room

      Built to be read from the back row

      A timer that only works on the person running it is not doing the job. The digits scale to the screen, the colour changes before the end, and fullscreen shows nothing else at all.

      A teacher presenting to a classroom of students
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      Photo by Quilia on Unsplash

      No ads on your big screen

      Ads pay for this page, and they stay on this page. The moment the timer goes fullscreen there is nothing on screen but the time — no banners, no navigation, no surprises in front of a room.

      • Fullscreen shows the timer alone
      • Ad sounds can never clash with the alarm
      • Saved times stay on your device — no account
      • Works with an ad blocker, and offline once loaded
      FAQ

      Questions people ask

      Anything we've missed?

      Tell us

      What is the best work-to-rest ratio for HIIT?

      Two-to-one, such as 30/15 or 40/20, for efforts you can repeat. One-to-two, such as 20/40, for genuinely maximal work. The harder the effort, the longer the rest needs to be.

      How long should a HIIT session be?

      Ten to twenty minutes of intervals is plenty. If you can comfortably sustain thirty, the intensity is not high enough for it to be interval training.

      Is 30/15 better than 40/20?

      They are the same ratio; 40/20 simply asks for a longer continuous effort. Start at 30/15 and move up when you can hold output across every round.

      Will the screen stay on during a session?

      Yes. The timer holds a wake lock while it runs, so a twenty-minute session stays on the phone or the gym TV without the display sleeping.

      Time something specific

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