40/20 HIIT Timer

Any work/rest ratio, any rounds - sounds, presets, and nothing to install.

Rated 4.6 out of 5 from 671 ratings
Work duration in minutes and seconds
Rest duration in minutes and seconds
Rest duration between sets in minutes and seconds
Popular:Tabata 20/10EMOM 1045/15 HIIT10-min AMRAP
Scan to open this timer on the gym TV
Embed this timer

How to use this HIIT Timer

Set your work interval, your rest interval, and the number of rounds. Add sets with a break between them if you're running multiple blocks. Hit start: a bell opens work, and 3-2-1 countdown beeps carry you into every switch. Every configuration is a shareable link.

Open a preset on a gym TV's browser and run it full-screen, or keep it full-screen on your phone - the display stays awake through the last round.

Quick presets

What is HIIT - and why the ratio is the whole workout

HIIT (high-intensity interval training) alternates hard work with recovery, and the work-to-rest ratio decides what any HIIT workout is actually training:

  1. Short work with equal rest (30/30) builds repeatable speed.
  2. Longer work with short rest (45/15, 60/30) builds conditioning under fatigue.
  3. Long intervals with long rest (the 4x4 "Norwegian" protocol) push aerobic capacity.

A HIIT timer exists because those switches come every 10-60 seconds and nobody counts them accurately at 90% heart rate - and every ratio below is one tap away in the workout timer hub.

Ratio
Example
Trains
Best for
1:130/30, 60/60Repeatable powerBeginners, skill-based movements
2:140/20, 60/30ConditioningMost general HIIT workouts
3:145/15Work capacity under fatigueAdvanced conditioning, class formats
4:140/10Near-Tabata densityShort, brutal finishers
4x4240/180VO2maxRunners, rowers, cyclists

Full ratio-by-goal programming lives in our HIIT intervals chart. For the fixed 20/10 protocol, use the Tabata timer, and for minute-based work, the EMOM timer.

Sounds - and music that follows the intervals

Cue sounds built in: a bell opens each work interval, and countdown beeps carry you into every switch - loud enough for a garage or a full class.

The part no other HIIT timer has: in FitVizPro on iOS and FitViz on Android, FitBeats plays licensed mixes in a dedicated high-output zone that shifts intensity with the intervals - energy pushes on work, drops on rest, no DJ-ing between rounds. Voice cues and pick-your-pack sound options live there too. It's why classes running this free HIIT timer on a gym display sound as sharp as they look.

3 HIIT workouts to run right now

Beginner Engine

Bike or bodyweight squats, same pace every round - 30 seconds on, 30 seconds off, 10 rounds, about 10 minutes.

Start the 30/30 HIIT →

Classic Conditioning

Rower, burpees, KB swings, mountain climbers rotating each round - 40 seconds on, 20 seconds off, 8 rounds, two blocks with a 60-second break between them, about 17 minutes.

Start the 40/20 x8, Two Blocks →

4x4 Engine

4 minutes hard, 3 minutes easy, four times, on any machine - about 25 minutes.

Start the 4x4 HIIT →

Why this free HIIT timer

Free, no ads, no signup

The interval doesn't pause for an ad mid-round.

Any ratio

Set custom work, rest, and rounds, or start from a preset - anything from a 10-second sprint to a 4-minute effort.

Shareable presets

Every configuration is a URL you can text to an athlete.

Runs full-screen on any screen

Open a preset on a gym TV's browser and run it full-screen for whole-class setups. For true casting from a phone or tablet, the FitViz Tv app casts directly to the screen.

Every format

HIIT here, plus Tabata, EMOM, AMRAP and For Time in the workout timer hub.

Frequently Asked Questions

A HIIT timer runs alternating work and rest intervals automatically, with sound cues for each switch, so you train instead of watching a stopwatch. This one adds presets, sets with breaks, and shareable links.

Beginners do best with a 1:1 ratio like 30/30. General conditioning uses 2:1, such as 40/20. Advanced work capacity training uses 3:1, like 45/15. For aerobic capacity, the 4x4 protocol runs 4 minutes on and 3 minutes off. The ratio, not the movement, is the programming decision.

10 to 25 minutes of intervals is the effective range - 10 for beginners, 15 to 20 for most, 25 for advanced 4x4 work. A session that runs much longer usually means the intensity wasn't high enough.

Tabata is one fixed HIIT prescription, 20 seconds on and 10 seconds off for 8 rounds at maximal effort. A HIIT timer takes any ratio. This tool runs both, and the 20/10 preset opens the dedicated Tabata timer.

Sound cues are built in: a bell opens each work interval and countdown beeps carry you into every switch. Voice cues and FitBeats interval-synced music are in FitVizPro on iOS and FitViz on Android.

Open a preset URL in the TV's browser and run it full-screen - the display stays awake through the final round. For actual casting from a phone or tablet, the FitViz Tv app casts directly; for synced multi-screen classes with the workout displayed alongside, that's the Fit Viz workout display.

Completely - no ads, no account, nothing to install. Built by Fit Viz, whose gym platform also starts free.

30 seconds work and 30 seconds rest for 8 to 10 rounds - the 30/30 preset. Add rounds before shortening rest.

Further Reading

Put this on every screen

This timer is free forever. Fit Viz runs it on gym TVs alongside the workout, scheduling, and the rest of the room.

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40/20 HIIT Timer: 40s Work, 20s Rest, 8 Rounds | Fit Viz