00:00
30-Second Timer
Thirty seconds is long enough for one exercise interval, one stretch, or one quadrant of tooth-brushing — and short enough that you will want an audible signal rather than watching the clock. The timer below starts automatically.
30/30 intervals
Ten rounds of 30 seconds hard effort and 30 seconds easy — a 10-minute beginner interval session.
Interval timer (work / rest rounds)
No active timers. Start one above or pick a preset.
Shortcuts: Space pause/resume · R reset · + add a minute · F fullscreen · Esc silence. They act on the timer that ends soonest.
30 seconds at a glance
- Started now, it ends at
- —
- In seconds
- 30
- In milliseconds
- 30,000
- In minutes
- 0.5
- Share of an hour
- 0.83%
- Share of a day
- 0.03%
- Back-to-back per hour
- 120
What a 30-second timer is good for
- Static stretches: the American College of Sports Medicine suggests holding each stretch for 10–30 seconds.
- Brushing one quarter of your mouth — four rounds make the two minutes dentists recommend.
- Plank holds and wall sits when you are building up endurance.
- Speed rounds in quizzes, classroom games and stand-up updates.
30/30 intervals: the full routine
Ten rounds of 30 seconds hard effort and 30 seconds easy — a 10-minute beginner interval session. Press Start 30/30 intervals above and the timer runs every step in order, with a short cue between steps and the current step in the browser tab title.
| # | Step | Length | Starts at |
|---|---|---|---|
| 1 | Work 1/10 | 30 s | 0:00 |
| 2 | Rest | 30 s | 0:30 |
| 3 | Work 2/10 | 30 s | 1:00 |
| 4 | Rest | 30 s | 1:30 |
| 5 | Work 3/10 | 30 s | 2:00 |
| 6 | Rest | 30 s | 2:30 |
| 7 | Work 4/10 | 30 s | 3:00 |
| 8 | Rest | 30 s | 3:30 |
| 9 | Work 5/10 | 30 s | 4:00 |
| 10 | Rest | 30 s | 4:30 |
| 11 | Work 6/10 | 30 s | 5:00 |
| 12 | Rest | 30 s | 5:30 |
| 13 | Work 7/10 | 30 s | 6:00 |
| 14 | Rest | 30 s | 6:30 |
| 15 | Work 8/10 | 30 s | 7:00 |
| 16 | Rest | 30 s | 7:30 |
| 17 | Work 9/10 | 30 s | 8:00 |
| 18 | Rest | 30 s | 8:30 |
| 19 | Work 10/10 | 30 s | 9:00 |
| Total | 9 min 30 s | ||
Need different lengths? Open Interval timer in the tool to set your own work, rest and round counts.
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