Sleep Calculator
Find bedtime or wake-up times using 90-minute sleep cycles.
Disclaimer: Sleep needs vary. This tool is for planning and does not replace medical advice.
Sleep Calculator
This calculator auto-updates when values change.
Suggested bedtimes
21:45, 23:15, 00:45
These times aim to align wake-up with 90-minute sleep cycles.
6 cycles
21:45
5 cycles
23:15
4 cycles
00:45
Disclaimer: Sleep needs vary. Use this as a planning guide only.
About This Sleep Calculator
This sleep calculator estimates bedtime and wake-up options based on 90-minute sleep cycles.
It includes a fall-asleep buffer so suggested times are easier to plan around.
How to Use This Calculator
- 1
Enter your details
Fill in the inputs with realistic values for your situation.
- 2
Review the result
The calculator updates the main result and supporting breakdown as values change.
- 3
Adjust and compare
Change the numbers to test different scenarios or planning options.
Frequently Asked Questions
What does the Sleep Calculator do?v
Find bedtime or wake-up times using 90-minute sleep cycles.
Are the results exact?v
No. Results are estimates based on the values you enter and should be used for general planning.