Sleep Calculator

Calculate optimal bedtimes and wake times based on 90-minute sleep cycles and your age. Wake up feeling refreshed by completing full cycles.

years
6:30 AM

Adult (18-64 years)

You need 7-9 hours of sleep per night for optimal health.

Best BedtimeAdult (18-64 years)

—

Adjust your time

Sleep Duration Scale for Adult (18-64 years)

4h6h8h10h12h
Optimal: 7-9h
Too ShortMinimalOptimalOversleep

All Bedtime Options

Sleep Tips

  • • Keep a consistent sleep schedule, even on weekends
  • • Avoid caffeine 6+ hours before bedtime
  • • Create a dark, cool, quiet sleeping environment
  • • Avoid screens 1 hour before bed
Documentation

How It Works

Sleep occurs in cycles of approximately 90 minutes each. Each cycle includes light sleep, deep sleep, and REM (dreaming) stages. Waking up at the end of a complete cycle helps you feel more refreshed.

The Formula

Bedtime + 15min + (Cycles × 90min) = Wake Time

Age-Based Recommendations

Newborns (0-1): 14-17 hours

Toddlers (1-2): 11-14 hours

Preschool (3-5): 10-13 hours

School-age (6-13): 9-11 hours

Teens (14-17): 8-10 hours

Adults (18-64): 7-9 hours

Older Adults (65+): 7-8 hours

Source: National Sleep Foundation