REM Sleep Calculator

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REM Sleep Calculator is a calculator that calculates and recommends optimal bedtimes and wake-up times based on sleep cycles. Wake up refreshed by following your REM sleep cycle!

Bedtime → Recommended Wake-up Time

Wake-up Time → Recommended Bedtime

What is the REM Sleep Cycle?

REM sleep (Rapid Eye Movement) and NREM sleep (Non-Rapid Eye Movement) are the two main stages of sleep. One complete sleep cycle lasts approximately 90 minutes(1.5 hour) and typically repeats 4 to 6 times throughout the night.

During a sleep cycle, the durations of NREM and REM sleep vary. In each cycle, REM sleep gradually becomes longer, while NREM sleep becomes shorter.

Throughout the sleep cycle, the ratio of NREM to REM sleep changes. In the early phases of sleep, NREM sleep is more prevalent, while REM sleep becomes longer in the later phases. This pattern contributes to better sleep quality and overall physical recovery.

How to Use the REM Sleep Calculator

This tool calculates the optimal wake-up and bedtime based on REM sleep cycles.

  1. Enter Bedtime: Select your desired bedtime, and it will recommend the wake-up time for a refreshed feeling.
  2. Enter Wake-up Time: Select your desired wake-up time, and it will recommend the optimal bedtime.
  3. Cycle-based Recommendation: Calculates in 1.5-hour increments (1-6 cycles) to provide the best sleep cycle.

Sleep Cycle and Wake-up Time

Generally, it is best to determine your wake-up time by considering a 1.5-hour cycle.

For example, if you fall asleep at 11:00 PM, the following wake-up times are recommended: