Sleep Calculator
Calculate optimal bedtimes and wake times based on sleep cycles
Sleep Cycle Calculator
Recommended Sleep by Age
| Age Group | Recommended | Acceptable |
|---|---|---|
| Newborn (0-3 mo) | 14-17 hrs | 11-19 hrs |
| Infant (4-11 mo) | 12-15 hrs | 10-18 hrs |
| Toddler (1-2 yrs) | 11-14 hrs | 9-16 hrs |
| Preschool (3-5 yrs) | 10-13 hrs | 8-14 hrs |
| School Age (6-13 yrs) | 9-11 hrs | 7-12 hrs |
| Teen (14-17 yrs) | 8-10 hrs | 7-11 hrs |
| Young Adult (18-25) | 7-9 hrs | 6-11 hrs |
| Adult (26-64) | 7-9 hrs | 6-10 hrs |
| Older Adult (65+) | 7-8 hrs | 5-9 hrs |
Tips for Better Sleep
How to Use Sleep Calculator
- Choose mode: 'I need to wake up at' or 'I want to sleep at'
- Enter your target time
- View optimal times based on 90-minute sleep cycles
Frequently Asked Questions
What is a sleep cycle and how long does it last?
A sleep cycle is a full rotation through light sleep, deep sleep, and REM sleep, lasting approximately 90 minutes. Most adults need 5-6 complete cycles (7.5-9 hours) per night for optimal rest.
Why is there a 14-minute sleep onset offset?
The average person takes about 14 minutes to fall asleep. The calculator factors this in so your alarm aligns with the end of a complete sleep cycle, not the middle of one.
Why do I feel tired even after 8 hours of sleep?
You may be waking up mid-cycle during deep sleep. This calculator helps you time your alarm to the end of a complete cycle, which is when you'll feel most refreshed โ even if it means slightly less total sleep.
What is the best time to go to sleep?
It depends on when you need to wake up. Enter your wake-up time and the calculator shows optimal bedtimes. Generally, sleeping before midnight gives better quality deep sleep due to natural circadian rhythms.