What fits in 45 minutes
- A school-length study block — one subject, notes closed at the bell.
- A serious gym session with warm-up included.
- Slow-roast checkpoint — chicken thighs, granola, focaccia's second proof.
- A deep-work block before the meeting begins.
The lesson-length block
Forty-five minutes is the sweet spot between the pomodoro's sprint and the hour's slog: long enough to load a hard problem fully into your head, short enough that the finish line stays visible. Students revising for exams do well mimicking the school bell at home — 45 on, 10 off — because recall practice under the same rhythm as the test transfers.
How this timer works
Press Start and the countdown anchors to your device's clock, so it stays second-accurate even in a background tab — the time remaining also ticks in the tab title. When it hits zero the display flashes and an alarm beeps three rounds (toggle the sound off if you prefer a silent flash). Use +1 min to extend on the fly, and fullscreen for a wall-visible display in classrooms and gyms.
Frequently asked questions
Why are school periods about 45 minutes?
The 45-minute lesson descends from Prussian school reform and survived because it roughly matches how long structured attention holds with one topic. It remains the default class length across much of the world — and a natural study-block size at home.
Is 45 minutes of exercise better than 30?
For steady-state cardio and strength volume, the extra 15 minutes adds meaningful training load. For habit-building, the best duration is the one you'll repeat — a kept 30 beats a skipped 45.
Will the timer keep running if I switch tabs?
Yes — the countdown is anchored to your device clock, not to the page being visible, so it stays accurate in a background tab. The remaining time also shows in the tab title so you can see it at a glance.
Does the alarm work with my phone on silent?
The alarm plays through the browser at your media volume. If your device is muted or the tab's sound is blocked, you'll still see the display flash and the tab title change — but for must-not-miss timing, unmute or keep the tab visible.