Sleep Calculator
Find the best bedtimes for your wake-up time using sleep cycles.
Result
Results are estimates for general information only and are not professional advice.
Sleep cycles
Sleep happens in roughly 90-minute cycles, and waking at the end of a cycle helps you feel more rested. Allowing about 15 minutes to fall asleep, this calculator suggests bedtimes that give you 6, 5 or 4 complete cycles before your alarm.
Frequently Asked Questions
What is the Sleep Calculator?
Find the best bedtimes for your wake-up time using sleep cycles. It runs instantly in your browser and is completely free.
Is the Sleep Calculator free and does it require signup?
Yes. Every calculator on Calculatis is 100% free with no registration, and the values you enter are never stored.
How accurate is the Sleep Calculator?
It uses standard, widely-accepted formulas. Results are reliable estimates for general use and are not a substitute for professional advice.