Sleep Cycle Calculator - Sleep Timer & Sleep Calculator

Free sleepytime, sleeptime, and sleepy time calculator. Calculate optimal sleep and wake times for better rest

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Sleep Cycle Calculator

Calculate optimal sleep and wake times for better rest

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Understanding Sleep Cycles - Sleep Calculator & Sleep Timer Guide

What are Sleep Cycles?

A sleep cycle consists of four stages of sleep that repeat throughout the night. Each cycle lasts approximately 90 minutes and includes both REM (Rapid Eye Movement) and non-REM sleep phases.

Waking up at the end of a complete sleep cycle helps you feel more refreshed and alert, while waking up in the middle of deep sleep can leave you feeling groggy and tired.

Sleep Cycle Stages

  • Stage 1: Light sleep transition (1-5 minutes)
  • Stage 2: Light sleep (10-25 minutes)
  • Stage 3: Deep sleep (20-40 minutes)
  • REM: Dream sleep (10-60 minutes)

Each complete cycle takes about 90 minutes, which is why our calculator uses 90-minute intervals.

How Many Sleep Cycles Do You Need?

4 Cycles (6 hours)

Minimum recommended for adults. Good for busy schedules but may lead to sleep debt over time.

5 Cycles (7.5 hours) ⭐

Optimal for most adults. Provides excellent recovery and mental clarity.

6 Cycles (9 hours)

Very restful sleep. Great for recovery from sleep debt or when you're feeling run down.

Tips for Better Sleep

  • Maintain a consistent sleep schedule
  • Create a relaxing bedtime routine
  • Keep your bedroom cool, dark, and quiet
  • Avoid screens 1 hour before bedtime
  • Limit caffeine and alcohol intake
  • Exercise regularly, but not close to bedtime

Understanding Sleep Debt

Sleep debt accumulates when you consistently get less sleep than your body needs. Our sleep debt calculator helps you understand how much sleep you might need to recover from accumulated sleep deprivation.

Chronic sleep debt can affect your mood, cognitive function, and overall health. It's important to prioritize getting adequate sleep regularly.

Age and Sleep Requirements

Sleep needs vary by age. Our sleep calculator by age feature helps determine the optimal amount of sleep for different age groups:

  • Newborns (0-3 months): 14-17 hours
  • Infants (4-11 months): 12-15 hours
  • Toddlers (1-2 years): 11-14 hours
  • Preschoolers (3-5 years): 10-13 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