😴 Free Tool

Sleep Calculator

Find the best time to wake up or go to sleep based on 90-minute sleep cycles — so you always wake up feeling refreshed and energised.

📋 Quick Summary

The average adult needs 7–9 hours of sleep per night (4–6 complete sleep cycles). Each sleep cycle lasts approximately 90 minutes. Waking up at the end of a complete cycle — rather than in the middle of one — helps you feel more alert and refreshed. This calculator shows you the ideal times to wake up or fall asleep based on 90-minute sleep cycles.

Set Wake Up Time

What time do you need to wake up?

Enter your wake-up time and we’ll calculate the best times to fall asleep tonight.

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