Timer+ 45 seconds work · 15 seconds rest
Free 45/15 HIIT Timer
The 45/15 split creates a demanding work-to-rest ratio for experienced trainees. Ten rounds provide a fast, focused workout with minimal downtime.
Select movements you can sustain safely under short recovery. Reduce the round count or extend rest when form begins to break down.
Workout builder
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7:40 total
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Add exercise names or start with generic work intervals.
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Take your named workouts with you
Timer+ adds voice announcements for exercise names, workout history, live time adjustments, widgets, and Apple Watch support. It is also more reliable when your phone is locked or the browser is in the background.
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Online HIIT timer FAQ
What is the 45/15 HIIT Timer?
The 45/15 split creates a demanding work-to-rest ratio for experienced trainees. Ten rounds provide a fast, focused workout with minimal downtime. Select movements you can sustain safely under short recovery. Reduce the round count or extend rest when form begins to break down.
Can I name each exercise in this HIIT timer?
Yes. Every work segment has an optional exercise field. Enter names such as Pushups, Sit-ups, or Jump Squats and the active exercise will appear during the workout.
Will the timer keep running when my phone is locked?
Browser behavior varies when a screen is locked or the page is put in the background. Timer+ is the better choice for reliable workouts with voice announcements, history, live adjustments, and Apple Watch support.