Sleep Calculator

Not sure when to go to bed or wake up? Our free Sleep Calculator uses proven 90-minute sleep cycles to recommend ideal bedtimes and wake-up times for you. Just enter your usual schedule or try the 'go to sleep now' option to get started.

What time do you plan to wake up?
What time do you plan to go to bed?

I want to go to sleep now...

How Sleep Calculator Works

Science Behind Sleep Cycles

This bedtime calculator helps you align with natural 90-minute sleep cycles. During each cycle, your body moves through different sleep stages, from light sleep to deep sleep and REM (Rapid Eye Movement) sleep. Waking up at the end of a cycle, rather than in the middle, helps you feel more refreshed.

Three Ways to Calculate

  1. Plan Your Wake-Up Time: Enter when you want to wake up, and we'll show you the best times to go to bed to complete full sleep cycles.
  2. Plan Your Bedtime: Enter when you plan to go to bed, and we'll recommend optimal wake-up times that align with your sleep cycles.
  3. Calculate from Now: Going to bed soon? Click this option to see the best times to wake up based on your sleep cycles starting now.

Recommended Sleep Duration

For optimal rest, aim for 7-9 hours of sleep, which equals 4-6 complete sleep cycles. Our calculator helps you achieve this by suggesting times that align with your natural sleep patterns.

Learn More About Sleep

Frequently Asked Questions

How does the Sleep Calculator determine bedtimes?

Our calculator works by counting back in 90-minute sleep cycles from your wake-up time, accounting for average time to fall asleep.

What is a 90-minute sleep cycle?

A 90-minute sleep cycle is the average length of one complete cycle through different sleep stages (light, deep, REM). Waking up at the end of a cycle helps you feel refreshed.