Sleep Calculator
Sleep cycles are roughly 90 minutes. Waking between cycles can help you feel more refreshed. Enter when you want to wake (or go to bed) and we suggest times based on cycle boundaries. Not a substitute for medical sleep advice.
Plan sleep or wake time
Choose mode and time, then click Calculate.
How it works
We add or subtract multiples of 90 minutes (plus ~15 minutes to fall asleep) from your target. For "wake at X" we suggest bedtimes; for "bed now" we suggest alarm times.
When to use it
Use it to plan bedtime or alarm so you wake after a full cycle. Cycle length varies by person; use as a guide.
Frequently asked questions
- Is 90 minutes exact for everyone? No. Cycle length varies. Use this as a guide and adjust to how you feel.
- What about fall-asleep time? We add about 15 minutes so you have time to fall asleep before the first cycle.