What is a Tabata timer?

Twenty seconds of maximum effort followed by ten seconds of rest, repeated eight times for four minutes total. It is a preset here, and it is only effective at genuinely high intensity.

What is a good work to rest ratio for HIIT?

Two to one, such as 40 seconds on and 20 off, is a widely used starting point. Shorter rest builds conditioning, longer rest lets you produce more power per round.

Will the timer keep running if my screen locks?

It tracks elapsed real time, so it stays accurate. Whether you hear it depends on your device, so keeping the screen awake during a session is safer if you are relying on the cue.

How many rounds should I do?

Enough that the last round looks like the first. If your final round falls apart, that is a sign you set either the intensity or the count too high, not that you need to push harder.

Interval timer

Set work and rest, choose your rounds, and go. Includes a Tabata preset.

Runs in your browser. Nothing is sent, saved, or shared.

Get ready

00:00

Round 1 of 8

Preset

Work

sec

Rest

sec

Rounds

Prepare

sec

Total session: 07:50

Pick a pace your last round can match. A session where round eight falls apart means the intensity was set too high, not that you needed to push harder.

What the presets are

Tabata is 20 seconds of work and 10 of rest, eight rounds, four minutes total. It came from a study of speed skaters and it is genuinely brutal when done at the intended intensity, which is close to all-out.

The more common circuit patterns are gentler: 40 on and 20 off, or 30 and 30, run for eight to twelve rounds. These are the ones most people actually use, and they leave enough in the tank to finish the session.

Prepare time exists for a reason

The countdown before round one is not decoration. Starting a hard interval while still reaching for your phone means the first round is half wasted, and the first round is usually the one that sets the pace for the rest.

Ten seconds is the default, which is enough to put the phone down and get into position.

Choosing work and rest honestly

The ratio decides what you are training. Short rest relative to work keeps the heart rate high and builds conditioning. Long rest lets you go harder in each round and favours power.

The common mistake is picking a ratio from a video, going all out for two rounds, and then coasting through six. A pace you can hold for every round teaches your body more than two impressive rounds and a collapse.

How to set up an interval timer

1
Pick a preset or set your own
Tabata and the common circuit splits are one tap. Custom lets you set any work and rest length.
2
Set the number of rounds
Eight is a common starting point. Pick a number you can finish at a consistent pace.
3
Use the prepare countdown
Ten seconds to get into position, so round one is not spent putting your phone down.
4
Watch the round counter, not the clock
The current round and phase are the large text. The colour changes between work and rest so you can read it across a room.

Questions people ask

What is a Tabata timer?: Twenty seconds of maximum effort followed by ten seconds of rest, repeated eight times for four minutes total. It is a preset here, and it is only effective at genuinely high intensity.
What is a good work to rest ratio for HIIT?: Two to one, such as 40 seconds on and 20 off, is a widely used starting point. Shorter rest builds conditioning, longer rest lets you produce more power per round.
Will the timer keep running if my screen locks?: It tracks elapsed real time, so it stays accurate. Whether you hear it depends on your device, so keeping the screen awake during a session is safer if you are relying on the cue.
How many rounds should I do?: Enough that the last round looks like the first. If your final round falls apart, that is a sign you set either the intensity or the count too high, not that you need to push harder.