Sleep Calculator

The sleep calculator uses the science of sleep cycles to recommend optimal bedtimes. During sleep the brain cycles through stages roughly every 90 minutes: light sleep, deep sleep (slow-wave), and REM (Rapid Eye Movement)

The calculator uses the standard published formula for sleep. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches, watts. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: Average sleep cycle = 90 minutes (can range 80–120 min). Each step in the calculation is shown so you can verify the result manually.