Classroom Timer
Run classroom activities, breaks and lesson stages with a large shared timer.
Options
Leave a field blank to disable that warning.
20:00
Set a duration and press Start.
Keyboard shortcuts
- Space — Start, pause or resume
- R — Restart from the full duration
- F — Enter or exit fullscreen
- M — Mute or unmute the alert
How this calculator works
Opens as a single quick timer — the 5, 10, 20, 45 and 60-minute presets cover most classroom activities without any setup. Enter a custom duration instead if none of the presets fit.
Switch to Stages for a full lesson plan: the default template moves through Instruction, Independent work and Review as separate timed blocks, advancing automatically from one to the next.
Warning thresholds (5 and 1 minute by default) give students visible notice before time runs out, and fullscreen mode makes the display readable from across the room on a shared screen or projector.
The tool is arithmetic only. Where legal, payroll, holiday, timezone or jurisdiction-specific rules matter, the page states what is and is not included.
Frequently asked questions
Can the timer change activities automatically?
Yes, when you switch to Stages — Classroom's stages default to automatic changes, so the timer moves from Instruction to Independent work to Review on its own as each block's time runs out.
Can I show this timer on a classroom projector?
Yes. Fullscreen mode enlarges the countdown for a shared screen or projector, readable from across the room.
Do I have to use stages, or can I just set a quick timer?
A quick single timer is the default — pick a preset or enter a custom duration and press Start. Stages are there when you want a full lesson plan instead, but they're never required.