Sleep cycle calculator
Calculate your sleep cycles
Enter a bedtime to see when approximately one through six sleep cycles would finish.
Choose your bedtime
Calculation runs in your browser. No account is required.
How long is a sleep cycle?
Sleep cycles are not all exactly the same length. For planning, this calculator lets you use an estimate between 80 and 100 minutes and then shows completion times for one through six cycles.
Calculation context
Sleep cycles vary
A 90-minute cycle is useful as a simple planning estimate, but it is not an exact rule for every person or every cycle.
Learn more from NHLBI / NIH and CDC sleep guidance .
Frequently asked questions
How long is one sleep cycle?
Cycle length varies. The calculator defaults to 90 minutes but allows an approximate range from 80 to 100 minutes.
How many sleep cycles happen in a night?
People commonly experience several sleep cycles during a night. This tool displays one through six cycles for planning purposes.
Is six sleep cycles always best?
Not necessarily. Individual sleep needs differ, and cycle timing is only one part of healthy sleep.