Interval Timer
Set repeating work/rest intervals for training circuits, study sprints, or timed drills.
Interval Timer
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View on AmazonHow the Interval Timer works
- Choose a preset length, or enter a custom duration.
- Press Start to begin.
- Press Pause to hold, or Reset to return to the starting value.
Formula / logic
Not formula-based — this is a live countdown or stopwatch driven by your device's clock, ticking down (or up) once per second.
Worked example
Selecting the 25-minute preset on a Pomodoro-style timer starts a focus block that automatically switches to a break once it reaches zero.
Frequently asked questions
How many rounds can I set?
You can set any number of rounds — the timer will cycle through work and rest periods until the set count is reached.
Will the timer alert me when it finishes?
The display updates to show the timer has finished; keep the tab visible or use your device's own notification/sound settings for an audible alert.
Can I change the preset lengths?
Yes — use the custom duration field to set any length beyond the quick-select presets.
Is the Interval Timer free to use?
Yes — every calculator on this site is free, with no sign-up or download required.
Does the Interval Timer work on mobile?
Yes, the layout and calculator both adapt to phone and tablet screens.