Countdown Timer Online

Set a countdown timer for any duration. Perfect for workouts, cooking, presentations, and study sessions.

Hours

Minutes

Seconds

00:05:00

About this calculator

Set hours, minutes and seconds and count down to zero, with an alert at the end. Great for workouts, presentations, cooking and study sessions.

Keep the tab open while it runs.

How to use it

Enter hours, minutes and seconds.
Press Start.
Press Reset to clear.

Time maths

Total seconds = hours × 3600 + minutes × 60 + seconds. A 90-minute timer is 5,400 seconds; a 1:30:00 display shows the same. The timer compares against the system clock so it stays accurate even if the page is briefly slowed.

Worked example

Examples

Egg boiling	7 minutes
Presentation slot	15 minutes
Workout interval	0:45

Tips and common mistakes

Set a few minutes' buffer before deadlines.
Turn the sound on.
Keep the tab visible.
Use for time-boxing tasks.
Reset before reusing.

Frequently asked questions

How do I set a 90-minute timer?

Enter 1 hour 30 minutes.

Does it ring?

Yes, when time is up.

Does it keep running in the background?

Mostly, but keep the tab open.

Is it accurate?

Yes.

Can I pause?

Use Reset and restart.

Is it free?