21 Minute Timer
This free 21 minute timer is ready to go — the countdown is already set to 21 minutes. Just press Start and watch it tick down. When it reaches zero a built-in alarm sound plays. No download, no signup; works on desktop and mobile.
What is this timer good for?
- A focused study or work sprint before a break
- A power nap (short enough to avoid grogginess)
- A home-workout circuit with timed sets
- Oven or air-fryer cooking steps
- A guided meditation or yoga sequence
How to use it
- The timer opens preset to 21 minutes.
- Adjust the hours, minutes or seconds for a different length.
- Press Start and the big display counts down.
- An alarm sounds at 00:00:00 — press Reset to run it again.
How long is 21 minutes?
21 minutes converts to 1,260 seconds, or about 35% of an hour. That is roughly 1.5% of a 24-hour day. Half of 21 minutes is 10 minutes 30 seconds, and two rounds back to back add up to 42 minutes.
Things that take about 21 minutes
- Set a 21-minute screen-time limit for kids and let the neutral alarm end the negotiation.
- Run a 21-minute study or deep-work block, then reward yourself with a short break.
- Do a 21-minute home workout video from warm-up to cooldown.
- Play a 21-minute podcast episode or language lesson while you cook or commute.
FAQ
Will it ring if I switch tabs?
Yes. The timer calibrates against your system clock, so it stays accurate even in a background tab. Just don't close the tab.
Do I need to download anything?
No. The timer runs entirely in your browser with no download, signup or plugin.
Can I change the duration?
Yes. Type any hours, minutes and seconds into the fields, or pick a related timer above.
Is it free?
Yes, it is completely free to use.
How many seconds are in 21 minutes?
21 minutes equals exactly 1,260 seconds (21 × 60).
What fraction of an hour is 21 minutes?
21 minutes is about 35% of an hour (21/60).
What if I need a bit more or less than 21 minutes?
Adjust the hours, minutes and seconds fields before pressing Start — the 21-minute preset is only a starting point, and the Related links above jump to neighbouring lengths.