Inputs
Live updatesSleep planning panel
Enter your wake-up time and cycle settings to see a practical bedtime estimate.
Cycle length and sleep onset time vary, so the result is a planning estimate.
Health toolRecommended bedtime
Sleep Cycle Calculator
Use this page to work backward from your wake-up time and pick a bedtime that fits your sleep cycles.
What you will get
Clear input, result, and explanation in one place
Recommended bedtime
The result shows a bedtime based on the number of sleep cycles you choose.
Cycle length and sleep onset time vary, so the result is a planning estimate.
Calculator
Enter your values and review the live result
Result
Recommended bedtime
The result shows a bedtime based on the number of sleep cycles you choose.
Current estimate
11:15 PM bedtime for 5 cycles
This assumes about 15 minutes to fall asleep and 90 minute cycles.
Supporting details
- 4 cycles: 12:45 AM
- 5 cycles: 11:15 PM
- 6 cycles: 9:45 PM
Explanation
How it works
Sleep planning is easier when wake-up time is the anchor, because the calculator can work backwards to a realistic bedtime.
Audience
Who should use this
Set your wake-up time, choose the number of cycles you want to complete, and use the suggested bedtime as a planning target.
Common questions
Why work backward from wake time?
Because most people need to protect a fixed wake time first and then choose a bedtime that fits.
Can I change the cycle length?
Yes. People do not all sleep in identical cycles, so the page keeps the setting editable.
Helpful guide
When BMI is enough, and when body fat is more useful
A simple guide to choosing between BMI, body-fat estimates, sleep timing, and training zone tools.
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