Sleep Calculator

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A sleep calculator helps you find better times to go to bed or wake up based on 90-minute sleep cycles.

Learn More About Sleep Cycles

If you want to understand how sleep cycles work and the best times to sleep and wake up, read our guide:

Sleep happens in cycles, not in one straight block. This calculator shows different options based on completing 4, 5, or 6 full sleep cycles.

In most cases, 5 or 6 sleep cycles are the best options for adults.

Yes. This calculator adds 15 minutes as the average time it takes to fall asleep.

This calculator gives estimated sleep and wake times based on average sleep cycles. It does not measure sleep quality or medical sleep problems.

A sleep cycle is a pattern your body goes through during sleep, lasting about 90 minutes and repeating several times each night.

Most adults need around 6 to 9 hours of sleep, which equals about 4 to 6 sleep cycles.

You may wake up in the middle of a sleep cycle, which can cause grogginess and fatigue.

It calculates your sleep times based on 90-minute sleep cycles to help you wake up feeling more refreshed.