About sleeptimer

sleeptimer is a sleep calculator. You set a bedtime or a wake-up, and it lists six clock times: 6 cycles down to 1, at 90 minutes each, shifted by the minutes you say you need to fall asleep.

It is a planning guide for the clock. It is not a medical device, not a diagnostic tool, and not a sleep tracker. It does not measure breathing, movement, heart rate, or sleep stages, and it does not decide whether a time is enough sleep for you. Questions about a sleep problem belong with a qualified clinician.

The same calculator is on the sleep cycle, bedtime, sleep time, sleep schedule, and REM pages. The REM page uses this same 90-minute average and says plainly that it cannot detect REM. The privacy page covers the one value stored in this browser: the fall-asleep minutes.