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.
Updated: April 21, 2026
Looking for a related estimate? Try Target Heart Rate Calculator or TDEE Calculator.
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 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
Because most people need to protect a fixed wake time first and then choose a bedtime that fits.
Yes. People do not all sleep in identical cycles, so the page keeps the setting editable.
Helpful guide
Heart rate zones explained
Understand target heart rate zones, resting heart rate, calorie burn, VO2 max, and how to use the right fitness calculator next.
Read guideRelated Calculators
Health
Target Heart Rate Calculator
Estimate target heart rate zones for fat burn, cardio, and peak effort using age and resting heart rate.
OpenHealth
TDEE Calculator
Estimate total daily energy expenditure from your age, weight, height, sex, and activity level.
OpenHealth
Water Intake Calculator
Estimate how much water to drink per day from body weight, activity level, and climate, with litres, cups, and hydration guidance.
OpenHealth
BMI Calculator
Check an adult BMI estimate, review the healthy weight range for your height, and switch between Metric and US inputs in a clear layout.
OpenHealth
Calorie Calculator
Estimate daily calories for maintenance, weight loss, or muscle gain using BMR, TDEE, activity level, and goal-based calorie targets.
OpenHealth
Macro Calculator
Calculate daily protein, carb, and fat grams for fat loss, maintenance, or muscle gain from calories, activity, and body metrics.
Open