Sleep Calculator

Our sleep calculator helps you find optimal bedtimes and wake times based on natural 90-minute sleep cycles. Wake up feeling refreshed by timing your sleep to complete full cycles rather than waking mid-cycle.

Understanding Sleep Cycles

Each sleep cycle lasts about 90 minutes and includes:

• Stage 1 (Light Sleep): Transition between wake and sleep
• Stage 2: Body temperature drops, heart rate slows
• Stage 3 (Deep Sleep): Physical restoration, immune function
• REM Sleep: Dreaming, memory consolidation, learning

How Many Cycles Do You Need?

• 5 cycles (7.5 hours): Minimum recommended for most adults
• 6 cycles (9 hours): Optimal for recovery and peak performance
• 4 cycles (6 hours): Minimum viable (not recommended long-term)

Calculator Modes

• Wake Time: Enter when you need to wake up → get optimal bedtimes
• Bedtime: Enter when you're going to bed → get optimal wake times
• Sleep Now: Going to bed now? → see best wake times

Tips for Better Sleep

• Account for 10-15 minutes to fall asleep when calculating
• Maintain consistent sleep and wake times daily
• Avoid screens 30-60 minutes before bed
• Keep your room cool, dark, and quiet

Related Health Calculators

Track your overall health with our calorie calculator for nutrition and BMI calculator for body composition. Good sleep supports both weight management and fitness.