Interval timer online
Set your work and rest. Keep each round in view.
Free to use, with no account. Choose your own pace and durations.
Build your session
Reset to edit a running or paused session. Reset keeps your chosen durations.
Your session
Ready
4 rounds
0:30
Total session: 3:00 (180 seconds), including final rest.
Session remaining: 3:00
Off by default. Enabling sound plays a short test tone. Device settings may silence it.
Ready when you are.
Switching tabs or apps pauses the timer. Select Resume when you return. Keep this page visible while timing; device sleep and background operation are not reliable. Reloading or leaving clears your session.
Plan the whole session before you start
Count the final rest
With no setup, 4 rounds of 30 seconds of work and 15 seconds of rest take 4 × (30 + 15) = 180 seconds, or 3 minutes, including final rest. Exclude final rest and the same session takes 165 seconds, or 2 minutes 45 seconds.
Add a setup, or skip rest
A 10-second setup adds 10 seconds once, before round 1. With zero rest, work rounds follow each other directly. For example, 4 rounds of 30-second work with a 10-second setup and no rest take 130 seconds.
Keep the timer separate from your records
This page does not save sessions or prescribe exercise intensity. Your settings stay in page memory; they are not sent, stored or added to the URL. For ongoing habits, make a printable habit tracker, try the web habit starter, or explore GoalifyNow.