Health & Fitness
Sleep Calculator
Find ideal bedtimes based on sleep cycles.
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
Frequently asked questions
How are bedtimes calculated?
We use 90-minute sleep cycles plus 15 minutes to fall asleep.
How many cycles should I aim for?
Most adults feel best with 4-6 sleep cycles.
Does this replace medical advice?
No. Use it as a guide and consult a professional for sleep issues.
Related tools
About this tool
Inputs
- Wake-up time
Results
- Recommended bedtimes
Not everyone remembers the formula, and that is exactly why the Sleep Calculator exists. It takes your raw figures and returns a meaningful answer. All you need to supply is wake- up time. From there, the tool determines recommended bedtimes. People frequently need to find ideal bedtimes based on sleep cycles but lack a quick way to do it — this tool fills that gap.
Age, sex, ethnicity, and fitness level all influence what counts as a healthy range for you. Health metrics give you a snapshot of where you stand, but they are not a diagnosis. No. Use it as a guide and consult a professional for sleep issues. Heart rate zones are typically expressed as percentages of maximum heart rate (220 minus age is a common approximation). Compare multiple scenarios by saving or noting each result before changing inputs.