😴 Sleep Cycle Calculator

Sleep runs in ~90-minute cycles. Waking up mid-cycle leaves you groggy. This calculator works backwards from your wake time to find bedtimes that end on a cycle boundary.

What time do you need to wake up?

Optimal Bedtimes

9:46 pm6 cycles

540 min sleep

11:16 pm5 cycles

450 min sleep

12:46 am4 cycles

360 min sleep

2:16 am3 cycles

270 min sleep

Assumes 14 min to fall asleep. The top option (6 cycles) is ideal.