Sleep Calculator
Calculate optimal sleep and wake times based on sleep cycles. Free, fast, and works entirely in your browser with no sign-up required.
Sleep Cycle Calculator
Find the optimal bedtime or wake time based on 90-minute sleep cycles.
Wake Up Time
Assumes ~15 minutes to fall asleep. Each sleep cycle is 90 minutes.
(Recommended)
(Good)
(Minimum)
(Nap only)
The Sleep Cycle
Recommended Sleep by Age
Sleep Hygiene Tips
- 1.Keep a consistent sleep schedule, even on weekends.
- 2.Avoid screens (blue light) 1 hour before bed.
- 3.Keep your room cool (65–68°F / 18–20°C).
- 4.Avoid caffeine after 2 PM.
- 5.Exercise regularly, but not within 2 hours of bedtime.
- 6.Limit alcohol — it disrupts REM sleep.
- 7.Use your bed only for sleep and intimacy.
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About Sleep Calculator
Sleep Calculator is a free, browser-based tool in our Health & Fitness Tools collection. Everything runs locally on your device — no uploads, no sign-up, and your data stays private.