40 Minute Timer

Press Start to count down 40 minutes.

This free 40 minute timer counts down 40 minutes with a shrinking red disc you can read at a glance. 40 minutes is 2,400 seconds (two thousand four hundred seconds). It matches a school lesson in many countries, a deep work block and the playing time of a college basketball game.

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What a 40 minute timer is good for

Forty minutes is the standard lesson length in many school systems, including much of Europe and Asia. It is also exactly the game clock of a US college basketball game, two halves of twenty minutes.

A school lesson

Teachers can project the timer at the start of a forty minute lesson so pupils see how the time is shared between activities.

A deep work block

Forty minutes of uninterrupted work, then a ten minute break, gives a rhythm close to the school day.

College basketball

An NCAA men’s game has two twenty minute halves, forty minutes of game clock in all.

Roast potatoes

Par-boiled roast potatoes need about forty minutes in a hot oven to turn crisp.

To pace yourself, glance at the disc rather than the numbers. With the 40 minute timer running, half the colour has gone after 20 minutes, and when only a quarter is left you have 10 minutes to wrap up. Open fullscreen if the timer needs to be read across a room, and add a label so everyone knows what the 40 minutes are for.

How to use the 40 minute timer

  1. It is ready

    The dial is already set to 40 minutes. To change it, drag the disc, tap a preset or open Custom.

  2. Press Start

    Or press the Space bar. The red disc shrinks back towards 12 o’clock as the time runs down.

  3. Watch the disc

    Read the time left at a glance, or open fullscreen for a big dial that fills the screen.

  4. Time’s up

    Your alarm plays until you press Stop. Press Reset or R to run the same time again.

40 minutes in other units

40 minutes equals
Seconds2,400
Minutes40
Hours0.6667
Fraction of a day1/36

Why use this timer

Why a visual timer helps

A shrinking disc turns time into something you can see. You read how much is left at a glance, without doing sums on a clock, and an invisible deadline feels less stressful when you can watch it approach. That is why visual timers are a staple in classrooms and are widely used by people with ADHD and autistic children and adults. Read our guide to using a visual timer, how it helps with ADHD time blindness, classroom transitions and autism.

Why this timer is accurate

The countdown is anchored to your device clock rather than counted in animation frames. It does not drift if you switch tabs or your screen sleeps: it keeps running in the background and still sounds the alarm on time. When you come back, the disc jumps straight to the correct position.

Frequently asked questions

There are 2,400 seconds in 40 minutes. That is 0.6667 of an hour, or two thousand four hundred seconds written out.

A forty minute school lesson, a deep work block before a break, timing a college basketball scrimmage or crisping roast potatoes.

Yes. The 40 minute countdown is anchored to your device clock rather than counted frame by frame, so it stays accurate in a background tab and the alarm still fires when the 40 minutes are up.

No. The 40 minute timer runs in your browser on phone, tablet and desktop. It is free, and there is no account, app or download.

Yes. Press the fullscreen button or the F key. The dial fills the screen, so the remaining part of the 40 minutes is readable from the back of the room.

Yes, once this page has loaded. Nothing is sent over the network while the 40 minutes count down, so a dropped connection will not stop the timer.

In many countries, yes. Lessons of forty to forty-five minutes are common in European and Asian schools, while many US and UK secondary schools use fifty to sixty minutes.

When the 40 minutes are up the disc is empty, the screen shows Time’s up! and your alarm plays until you press Stop. It stops by itself after five minutes.

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