Time Tools

Sleep Cycles

Calculate your optimal sleep and wake times based on sleep cycles. Use this free tool to improve your sleep quality and wake up refreshed.

Sleep calculator

Need to wake up at a certain time? Let's calculate the best time for you to fall asleep.

or

If you sleep now, find out the perfect time to wake up.

Based on the time that you wish to wake up, falling asleep at one of these times is the best:

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Take note:

Plan ahead because it takes about 14 minutes for an average human to fall asleep.
This app works by counting backwards in sleep cycles.
Completing a sleep cycle before waking up will make you feel refreshed and active compared to waking up in the middle of it which will make you feel groggy.

If you know when you'll fall asleep, but not when you'll wake up, try this

If you fall asleep now, consider waking up at one of these times:

or or or or or

Take note:

One complete sleep cycle lasts about 90 to 110 minutes.
Five to six complete sleep cycles can give you a goodnight's sleep.
Waking up in the middle of a sleep cycle can make you feel dizzy and disoriented.

If you know when you'll fall asleep, but not when you'll wake up, try this this

I plan to fall a sleep at...

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How sleep cycles work

A full sleep cycle lasts about 90 minutes. Waking at the end of a cycle — rather than in the middle — helps you feel refreshed instead of groggy. This tool counts backward (or forward) in 90-minute blocks.

Cycle~90 minutes

Fall asleep+14 min buffer

Ideal night5–6 cycles

Wake timeend of cycle

Use wake-up mode when you know when you need to get up, or sleep now to find the best wake times if you're heading to bed right away.