Sleep now calculator
If I sleep now, what time should I wake up?
Use your current local time to see a few possible wake-up windows. Longer-rest choices come first.
The quick answer
Count forward, but leave room to fall asleep
This calculator starts at the time on your device, adds your selected fall-asleep estimate, and then counts forward in approximate 90-minute blocks. Results include the calendar date so late-night calculations stay clear after midnight.
If you have a choice, favor more sleep opportunity over a precise cycle boundary. A clock can add 90-minute blocks; it cannot know your actual sleep stages tonight.
Example: if your device says 11:30 PM and you select 15 minutes to fall asleep, the tool treats sleep as starting around 11:45 PM. That makes 4:15 AM, 5:45 AM, 7:15 AM, and 8:45 AM the 3-, 4-, 5-, and 6-cycle windows.
Read the calculation methodology and limitations.
About sleeping now and waking later
If I go to sleep now, when should I wake up?
Press the button above to use your device's current local time. The calculator adds your estimated time to fall asleep and then shows options after 3, 4, 5, and 6 approximate sleep cycles.
Should I choose 5 or 6 sleep cycles?
The 5- and 6-cycle options provide more sleep opportunity than the shorter choices. Choose based on the time you actually have and how much rest your schedule allows.
Will waking between cycles make me feel refreshed?
Not necessarily. Cycle timing varies and many things affect how you feel in the morning. The times are rough planning suggestions, not a guarantee about sleep quality or alertness.
Does this calculator know my timezone?
It uses the current time reported by your device. No location or account is required.