Sleep Calculator

Free sleep calculator. Enter your wake-up time or bedtime to find the ideal sleep schedule based on 90-minute sleep cycles for better rest. Use our free calcula

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Option 1 (5 cycles, 7.5h) hesaplanacak
Option 2 (6 cycles, 9h) hesaplanacak
Option 3 (4 cycles, 6h) hesaplanacak
Recommended Cycles hesaplanacak

How Sleep Cycles Work

Sleep is structured in 90-minute cycles, each consisting of light sleep, deep sleep, and REM (Rapid Eye Movement) sleep. Waking up at the end of a complete cycle — rather than in the middle of deep sleep — is the key to feeling refreshed and alert in the morning.

Calculate Your Ideal Bedtime

To wake up at a specific time feeling rested, count back in 90-minute increments:

  • Wake at 7:00 AM → Sleep at: 5:30 AM / 4:00 AM / 2:30 AM / 1:00 AM / 11:30 PM / 10:00 PM
  • Aim for 5–6 complete cycles (7.5–9 hours) for optimal rest
  • Add 15 minutes to each time to account for falling asleep

Recommended Sleep by Age (National Sleep Foundation)

Age GroupRecommended Sleep
Newborns (0–3 months)14–17 hours
Infants (4–11 months)12–15 hours
Toddlers (1–2 years)11–14 hours
School-age (6–13 years)9–11 hours
Teenagers (14–17 years)8–10 hours
Adults (18–64 years)7–9 hours
Older adults (65+)7–8 hours

Sleep Hygiene Tips

  • Maintain a consistent sleep/wake schedule, even on weekends
  • Avoid caffeine after 2 PM
  • Keep the bedroom cool (16–19 degrees C / 60–67 degrees F)
  • Avoid blue light (screens) for 1 hour before bed
  • Avoid alcohol — it fragments sleep architecture even if it aids falling asleep

How to Use This Calculator

Using our calculator is simple: enter the required values into the input fields and click the calculate button. Results are displayed instantly on screen. You can adjust the values and recalculate to compare different scenarios and find the best option for your situation.

Frequently Asked Questions

QuestionAnswer
How accurate are the results?We use standard formulas and up-to-date 2025 rates. Individual circumstances may vary slightly.
Is this calculator free?Yes, completely free and no registration required.
What should I do for exact figures?For precise information, consult a relevant professional or official authority.
Does it work on mobile devices?Yes, it works seamlessly on all devices and screen sizes.

Important Notes

This calculator is provided for informational purposes only. For legal, financial, or medical decisions, always seek advice from qualified professionals. Calculation results do not constitute official documents. Legislative changes may affect results; please visit the relevant official website for the most up-to-date information. Our calculators are regularly updated to reflect current regulations and rates.

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Frequently Asked Questions

One complete sleep cycle lasts approximately 90 minutes. It includes light sleep, deep sleep (slow-wave), and REM sleep. Adults typically go through 4-6 cycles per night.
The CDC recommends 7-9 hours for adults aged 18-64. Older adults (65+) need 7-8 hours. Less than 7 hours regularly is associated with health risks.
Yes — waking at the end of a complete cycle feels better than being jolted from deep sleep. 6 hours (4 cycles) can feel more refreshing than 7 hours of interrupted sleep.