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45 Minute Timer
A 45:00 countdown, ready to go: press Start (or Space) and the alarm rings after three quarters of an hour. A popular length for classes, deep-work sessions, workouts and baking.
45:00
Ready
Presets
Shortcuts: Space start / pause · R reset · F fullscreen. Add ?m=20 to the address for a custom length. Keep this tab open; the countdown stays accurate in the background.
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How to use the 45 Minute Timer
- Press Start or hit the Space bar. The 45:00 countdown begins immediately.
- Want a reminder midway? Tick Soft chime at the halfway mark to hear a gentle chime at 22:30 left.
- Fine-tune the length with the ± buttons or pick another preset.
- Choose an alarm sound and volume, then press Play test sound to check you can hear it.
- When time is up, press Stop alarm or Space. Press R to reset to 45:00.
How long is 45 minute?
| Measure | 45 Minute equals |
|---|---|
| Minutes | 45 min |
| Seconds | 2,700 s |
| Milliseconds | 2,700,000 ms |
| Hours | 0.75 h |
| Share of a day | 3.12% (1/32 of a day) |
| Walking at 5 km/h (3.1 mph) | about 3.8 km (2.3 mi) |
| Speaking at 130 words per minute | about 5,850 words |
| Reading at 230 words per minute | about 10,350 words |
What you can do in 45 minute
| Activity | Why 45 minute works |
|---|---|
| Class period | Many school lessons last 45 minutes |
| Deep work | A long focus block, for example 45 minutes on and 15 minutes off |
| Workout | A full gym session or a long run |
| Baking | Banana bread, many cakes and casseroles take 40 to 50 minutes |
| Half of a football match | Each half of a soccer match is 45 minutes plus stoppage time |
| Exam practice | Time yourself on a past paper section |
How the countdown keeps exact time
When you press Start, the timer records the end moment as start time + 2,700,000 ms on the browser's monotonic clock (performance.now()). Every screen update subtracts the current time from that end moment instead of counting ticks, so a throttled background tab or a busy computer cannot make it fall behind. Pausing stores the time left, and Resume sets a new end moment that far in the future.
Frequently asked questions
How do I set a timer for 45 minutes?
The timer opens at 45:00. Press Start or Space and the alarm sounds when it reaches 0:00.
How many seconds are in 45 minutes?
45 minutes is 2,700 seconds or 2,700,000 milliseconds, which is 0.75 hours.
Why are study sessions often 45 minutes?
It is long enough to get deeply into a task and short enough to stay focused. Many people pair 45 minutes of work with a 10 to 15 minute break.
When does the halfway chime play?
When switched on, it plays once at 22:30 left, half of the 45 minutes.
Does the timer stay accurate for 45 minutes?
Yes. It calculates the time left from the clock and the stored end time, so it stays accurate even in a background tab. Keep the tab open and the computer awake.
Can I choose a different length?
Use the presets (15 to 60 minutes), the ±1 min buttons, or ?m= in the address, for example ?m=40.
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