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Space start / pause · R reset · F full screen · works with presentation clickers
A 45 second timer is a countdown that runs for 45 seconds and sounds an alarm when it reaches zero. This one starts on its own when the page opens and works full screen on a classroom projector, a laptop, or a phone.
- Length
- 45 seconds
- Equals
- 45 seconds is three quarters of a minute.
- 45 seconds from now
- shown under the timer as "Ends at"
- Alarm
- Bell, chime, beep, gentle tone, or silent
- Price
- Free, no sign-up, nothing to install
What to use a 45 second timer for
- Circuit workouts with 45 seconds of work and 15 seconds of rest
- Quick-write warm-ups at the start of a lesson
- Rapid partner quizzes
Using a 45 second timer in the classroom
A 45-second countdown is short enough that students stay locked on the task. Project it full screen, say the instruction once, and let the timer do the nagging for you.
Teaching with it? The classroom timer adds one-tap presets for common routines, and thevisual timer shows time as a shrinking disc for students who are still learning to read a clock.
How this timer works
- Starts by itself. The 45-second countdown begins when the page opens, so a bookmark is all you need.
- Full screen. Press F to fill the display. Nothing else is shown — no menus and no ads.
- Your choice of alarm. Pick a bell, chime, beep, or gentle tone, or run it silently.
- Four displays. Digital with a ring, a visual disc, a progress bar, or a traffic light that turns yellow and red.
- Shareable. "Copy link" saves your alarm and display choices in the link for students or colleagues.
Other timers
- 10 Second Timer
- 15 Second Timer
- 20 Second Timer
- 30 Second Timer
- 1 Minute Timer
- 90 Second Timer
- 2 Minute Timer
- 3 Minute Timer
- 4 Minute Timer
- 5 Minute Timer
- All timers →
45 Second Timer FAQ
How do I set a 45-second timer?
Open this page and the timer is already set: it starts counting down from 45 seconds as soon as it loads. Press the space bar or Pause to stop it, Reset to go back to 45 seconds, and F for full screen.
How long is 45 seconds?
45 seconds is three quarters of a minute.
How much time is left on my timer?
The time remaining is shown in the large digits and in the browser tab title, so you can check it even from another tab. The ring around the digits also shrinks as time runs out.
Can I show this 45 second timer on a projector or smart board?
Yes. Press F or the Full screen button and the countdown fills the whole display with no ads or menus. A presentation clicker works too: the "next" button starts and pauses the timer.
Will the alarm still ring if I switch to another tab?
Yes. The timer follows your device clock, so it stays accurate in a background tab. Click anywhere on the page once so your browser allows the alarm sound.
Last reviewed by the TeachTimer team · How we build and check our tools