90 Minute Timer

Press Start to count down 90 minutes.

This free 90 minute timer counts down 90 minutes with a shrinking red disc you can read at a glance. 90 minutes is 5,400 seconds (five thousand four hundred seconds). It is a full sleep cycle, a university seminar, a football match and a deep work block.

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What a 90 minute timer is good for

Ninety minutes is roughly the length of one human sleep cycle. Through the night the brain moves through light sleep, deep sleep and REM sleep in cycles that average about ninety minutes, which is why naps and wake-up times planned in ninety minute steps can feel easier.

A full sleep cycle

A ninety minute nap lets you complete a whole cycle and wake from lighter sleep, avoiding the sleep inertia of waking mid-cycle.

Deep work

Researchers who studied expert violinists found the best practised in sessions of about ninety minutes. Many writers and programmers use the same length.

A football match

A professional football match is two halves of forty-five minutes, ninety minutes before stoppage time.

A long seminar

Many university seminars and workshops are scheduled for an hour and a half.

Slow roasting

A larger joint of about 1.5 kilograms roasts in around ninety minutes at 180°C.

To pace yourself, glance at the disc rather than the numbers. With the 90 minute timer running, half the colour has gone after 45 minutes, and when only a quarter is left you have 22 minutes 30 seconds to wrap up. Open fullscreen if the timer needs to be read across a room, and add a label so everyone knows what the 90 minutes are for.

How to use the 90 minute timer

  1. It is ready

    The dial is already set to 90 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.

90 minutes in other units

90 minutes equals
Seconds5,400
Minutes90
Hours1.5
Fraction of a day1/16

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 5,400 seconds in 90 minutes, which is 1 hour 30 minutes.

A full ninety minute sleep cycle nap, a deep work session, timing a football match, a university seminar or slow-roasting a larger joint.

Yes. The 90 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 90 minutes are up.

No. The 90 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 90 minutes is readable from the back of the room.

Yes, once this page has loaded. Nothing is sent over the network while the 90 minutes count down, so a dropped connection will not stop the timer.

Sleep moves through light, deep and REM stages in repeating cycles. Each cycle averages about ninety minutes in adults, though it varies between people and through the night.

It is much longer than a 25 minute Pomodoro. Ninety minutes is closer to an ultradian rhythm block, usually followed by a fifteen to twenty minute break.

It is longer than a power nap, but it is a good length for a full-cycle nap that ends in light sleep.

An eight hour day fits about four ninety minute blocks with breaks. Many people find two or three deep work blocks is the realistic maximum.

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