Sleep cycle guide
Sleep cycle calculator
Plan a bedtime or alarm around estimated cycles of non-REM and REM sleep. Our tool uses 90 minutes as a simple midpoint, while real cycles commonly vary across the night.
Plan your sleep schedule
Open the calculatorWhat is a sleep cycle?
During sleep, the brain and body move through non-REM stages and REM sleep. The National Heart, Lung, and Blood Institute describes a cycle as restarting about every 80 to 100 minutes, with four to six cycles during a typical night.
Why calculators use 90 minutes
Ninety minutes is easy to use as a planning estimate because it sits within that range. It is not a measurement of your personal cycle length. Stress, age, sleep debt, medication and other factors can affect sleep patterns.
How many cycles should you get?
Instead of targeting a rigid number, start with the recommended total sleep for your age. Many adult schedules work out to roughly five or six estimated cycles, but enough good-quality sleep should remain the priority.
Source: NHLBI: Sleep phases and stages.