Sleep Timing Tools

Free calculators for bedtime, wake time, sleep cycles, caffeine cutoff, and nap length. All based on established sleep science, no account needed.

Sleep Cycle Calculator

Wake time → bedtimes. The general-purpose 90-minute-cycle planner with a tunable cycle length for chronotype edge cases.

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Bedtime Calculator

Wake time → bedtimes, but with an age-group selector (child / teen / adult / older) so the recommended sleep length lands at 5 or 6 cycles automatically.

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Wake Up Time Calculator

Bedtime → alarm times. The reverse direction of the Sleep Cycle and Bedtime calculators, for when you already know what time you'll be in bed.

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Caffeine Cutoff Calculator

Find the latest safe time to drink coffee based on caffeine half-life and your metabolic sensitivity.

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Nap Duration Calculator

How long should you nap? Get the right nap length for your goal, alertness, memory, or recovery.

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Other calculator clusters:

Health Tools →Situation Tools →Circadian Tools →All Calculators →

Educational information, not medical advice. Consult a healthcare provider for sleep disorders or before taking any supplement.