Health Calculator
Sleep Cycle Calculator
Find ideal bedtimes or wake times using 4 to 6 sleep cycles, a custom cycle length, and the time you usually need to fall asleep.
How this sleep cycle calculator works
The calculator uses a configurable cycle length, defaulting to 90 minutes, and adds your fall-asleep time so the suggested bedtimes or wake times line up closer to cycle endings.
How to use the result
Most people compare 4, 5, and 6 cycles. Shorter nights may be more practical, while 5 to 6 cycles are often a better fit when you want more complete rest.
Health note
Sleep timing tools can help with planning, but they do not replace medical advice. If sleep quality is consistently poor, look beyond cycle timing alone.