HIIT Timer
Results are estimates only and may not reflect your individual needs. This tool is for educational purposes only and is not medical advice.
A free in-browser HIIT interval timer. Set your work time, rest time, and number of rounds.
Timer ready
Set your intervals and press Start Timer.
Why use this calculator
HIIT requires precise work-to-rest ratios to deliver its cardiovascular and metabolic benefits. Guessing the timing makes it harder to maintain intensity and track progress. This timer handles all the counting so you can focus entirely on the workout.
How to use this calculator
Set your work time, rest time, number of rounds, and an optional “get ready” countdown before the first round starts. Press Start Timer to begin. Use Pause to hold the timer and Stop to cancel.
What the result means
The timer alternates between work and rest phases for the number of rounds you set. A “get ready” phase lets you position yourself before the first work interval starts.
Important limitations
This is a browser-based timer. Keep the tab active to ensure accurate timing. Browser tab throttling may affect background-tab accuracy on some devices.
FAQ
What are good HIIT intervals for beginners?
20 seconds work / 40 seconds rest for 8 rounds is a classic beginner-friendly format.
What is Tabata?
Tabata is 20 seconds work / 10 seconds rest for 8 rounds — set those values in the form to replicate it.
High-intensity exercise carries inherent risk. Consult a healthcare professional before starting a new exercise programme.