Sleep Calculator: What Time Should I Go to Bed?
Waking up in the middle of a sleep cycle can leave you groggy, even after a full night in bed. Enter the time you need to wake up and our sleep calculator will suggest bedtimes that line up with natural sleep cycles.
We'll count from right now, plus about 15 minutes to fall asleep.
Times assume roughly 90-minute sleep cycles and about 15 minutes to fall asleep. Everyone is a little different — use these as a starting point.
How the sleep calculator works
During the night, you move through repeating sleep cycles, each lasting roughly 90 minutes. A cycle includes light sleep, deep sleep, and REM (dream) sleep. Waking up at the end of a cycle, when sleep is lighter, can feel easier than being jolted awake from deep sleep.
The calculator counts back (or forward) in 90-minute cycles and adds about 15 minutes for the time it typically takes to fall asleep. Five or six cycles, about 7.5 to 9 hours, is a healthy target for most adults.
How much sleep do you need?
The CDC recommends that adults get at least 7 hours of sleep per night. Teens and children need more. Your exact needs can vary, so notice how you feel during the day: if you’re relying on caffeine to function or dozing off easily, you may need more sleep.
Tips for using your results
- Pick one bedtime and stick with it. A consistent schedule matters more than hitting a perfect cycle.
- Start winding down 30–60 minutes earlier. Dim the lights and put screens away.
- Don’t stress about exact times. Sleep cycles vary from person to person and night to night, so use these times as a helpful guide, not a strict rule.
Having trouble falling asleep at your new bedtime? Read our guide on how to fall asleep fast or learn how to fix your sleep schedule.
This calculator is for general information and is not medical advice. If you have ongoing sleep problems, talk to a healthcare provider.