Sleep Calculator
Wake up refreshed — find the best bedtimes based on 90-minute sleep cycles.
🔄 Updated October 13, 2026
About the Sleep Calculator
The Sleep Calculator helps you track an important health number in seconds. Wake up refreshed — find the best bedtimes based on 90-minute sleep cycles. Results are estimates for awareness and planning — always consult a qualified professional for medical advice. You may also like the BMI Calculator and TDEE Calculator.
How to use this calculator
- Enter your numbers in the fields above.
- Results update instantly — no button to press, no page reload.
- Adjust the inputs to compare scenarios with the Sleep Calculator.
Keep exploring: BMI Calculator · Calorie (BMR) Calculator · Age Calculator · Pregnancy Calculator
Frequently asked questions
Why 90-minute cycles?
Waking at the end of a sleep cycle avoids grogginess compared to mid-cycle alarms.
Related tools
BMI CalculatorCheck your Body Mass Index and see which weight category you fall into. Calorie (BMR) CalculatorEstimate daily calorie needs from age, gender, height, weight and activity level. Age CalculatorFind your exact age in years, months and days from your date of birth. Pregnancy CalculatorTrack pregnancy week by week — enter LMP date to get due date, weeks… Ovulation CalculatorFind your fertile window, ovulation day and next expected period from cycle details. Body Fat CalculatorEstimate body fat percentage with the U.S. Navy tape-measure method.