Sleep Calculator
Choose a bedtime or wake-up time, then adjust your sleep-cycle length and time to fall asleep. These estimates help with planning; they are not medical advice.
When this tool is useful
Compare possible bedtimes or wake-up times using a simple cycle-based estimate. Total estimated sleep is the number of cycles multiplied by your chosen cycle length; time to fall asleep is added separately.
A practical example
With a 07:00 wake-up time, six 90-minute cycles and 15 minutes to fall asleep suggest getting into bed at 21:45 the previous evening. Changing either setting changes the estimate.
What to keep in mind
Real sleep cycles vary between people and during the night. Completing a calculated cycle does not guarantee feeling rested, and shorter options are not recommendations to restrict sleep. Persistent sleep problems deserve advice from a healthcare professional.
Common questions
Is time to fall asleep counted as sleep?
No. It shifts the suggested bedtime or wake-up time but is not included in the displayed sleep duration.
What happens when an option crosses midnight?
The time wraps to a 24-hour clock. Bedtimes may be on the previous day and wake-up times on the next day.
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