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Free sleep schedule tool
Find bedtime or wake-up options based on 90-minute sleep cycles and an average 15 minutes to fall asleep.
Sleep result
Five or six sleep cycles are usually the strongest planning targets.
Estimate only. Sleep needs vary by age, health, stress, light exposure, caffeine, and schedule consistency.
The calculator uses common 90-minute sleep cycle planning. For wake-up planning, it subtracts three, four, five, or six cycles from the wake-up time and also subtracts 15 minutes for falling asleep. For sleep-now planning, it starts with the current time, adds 15 minutes to fall asleep, then adds each cycle count.
Sleep moves through lighter sleep, deeper sleep, and REM sleep in repeating patterns. A 90-minute cycle is a simplified average, not a guarantee, but it is useful for planning alarm times that may avoid waking in the middle of deeper sleep.
The highlighted choices are five and six cycles, or about 7.5 to 9 hours of sleep after falling asleep. Four cycles can work for a shorter night, while three cycles is usually a fallback rather than a healthy routine.
This tool does not diagnose insomnia, sleep apnea, circadian rhythm disorders, or medical sleep issues. If sleep problems are persistent or severe, use this calculator only as a planning aid and talk with a qualified health professional.