Sleep Calculator

Calculate when to wake up based on your bedtime.

Or, if you plan to sleep at a specific time:

Select a mode and provide a time to get started.

The average human sleep cycle is 90 minutes. Waking up at the end of a cycle, rather than in the middle of it, helps you feel refreshed and alert. This calculator works with 90-minute increments and also considers an average of 15 minutes to fall asleep.

During sleep, your brain cycles through different stages (light, deep, REM). A full cycle takes about 90 minutes. Completing 5-6 full cycles (7.5 to 9 hours) is recommended for most adults.

This is a tool based on averages. Individual sleep cycles can vary. Use these results as a guideline to find what works best for you.