Sleep Calculator by Age – Estimate Bedtime, Wake-Up Time & Sleep Cycles
What time do you want to wake up?
This free sleep calculator helps you estimate the best time to go to bed or wake up based on natural 90-minute sleep cycles and your age. Use it as a sleep estimator to wake up feeling refreshed. You can also play rain sounds and calming sleep noise to help you fall asleep faster.
If you want to go to bed now...
Sleep Calculator Based on Natural Sleep Cycles
This sleep calculator helps you estimate the best time to go to bed or wake up by aligning your alarm with natural 90-minute sleep cycles. Waking up near the end of a cycle can help reduce grogginess and support a better morning routine.
Use this calculator for sleep by choosing your age and either your wake-up time or bedtime. You can also use it as a sleep estimator when going to bed now to find the most refreshing wake-up times.
How Much Sleep Do You Need by Age?
| Age Group | Recommended Sleep |
|---|---|
| Preschool (3–5) | 10–13 hours |
| School-age (6–12) | 9–12 hours |
| Teen (13–18) | 8–10 hours |
| Adult (19–64) | 7–9 hours |
| Older adult (65+) | 7–8 hours |
Sleep Calculator FAQs
How does this sleep calculator work by age?
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How does this sleep calculator work by age?
▼It estimates ideal bedtimes and wake-up times using 90-minute sleep cycles and a typical 15-minute fall-asleep buffer. You can also choose an age group to match general sleep recommendations.
Why are 90-minute sleep cycles used?
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Why are 90-minute sleep cycles used?
▼A full sleep cycle is often approximated at around 90 minutes. Waking closer to the end of a cycle can help you feel less groggy than waking mid-cycle.
What does the 15 minutes to fall asleep mean?
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What does the 15 minutes to fall asleep mean?
▼Many people take around 10–20 minutes to fall asleep. This calculator uses 15 minutes as a simple estimate before the first sleep cycle begins.
Can I use this sleep estimator if I go to bed now?
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Can I use this sleep estimator if I go to bed now?
▼Yes. Use the “go to bed now” option to estimate wake-up times that align with full sleep cycles.
Can I use this as a sleep estimator for naps?
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Can I use this as a sleep estimator for naps?
▼Yes. You can estimate wake-up times by aiming for 1–2 full cycles (about 90–180 minutes) depending on how long you want to rest.
Do the rain sounds play automatically?
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Do the rain sounds play automatically?
▼No. The rain sounds and other sleep noise require a tap/click to play, and you can tap again to stop.