Sleep calculator

Wake up refreshed by sleeping in full 90-minute cycles. Pick a wake-up time or a bedtime — we suggest the best moments. Nothing is uploaded.

Wake-up time

Everything runs in your browser. No upload, no sign-up.

How it works

STEP 1

Pick your mode

Set a wake-up time, or a bedtime (or tap “go to bed now”).

STEP 2

See the cycles

We count back or forward in 90-minute sleep cycles, plus ~15 minutes to fall asleep.

STEP 3

Pick a highlighted time

5–6 cycles is ideal for most adults. All private, nothing leaves your device.