How to use the Sleep Calculator
Choose your mode. If you have a fixed wake-up time (like a work alarm), pick I want to wake up at and enter the time — the calculator shows the ideal bedtimes to align with complete sleep cycles.
If you're going to bed now, pick I want to sleep now — it calculates the best times to set your alarm based on the current time plus 15 minutes to fall asleep.
When to use a sleep calculator
Waking up between sleep cycles instead of mid-cycle makes a real difference in how rested you feel. Use this tool when:
- →Setting a new alarm and wanting to wake up feeling refreshed
- →Adjusting your sleep schedule for a new job or early meeting
- →Planning a nap — 90-minute naps are ideal for avoiding grogginess
- →Recovering from jet lag by syncing to a new time zone's cycles