Is it possible to get enough sleep in 6 hours (4 cycles)?

Yes, but this is the lower limit of the norm. For full recovery, doctors recommend 5-6 cycles (7.5 - 9 hours).

Why do I wake up before my alarm?

Your body senses the end of your sleep cycle and naturally wakes up. This is a sign of a healthy sleep pattern.

Why specify the time to fall asleep?

Cycle calculations begin not from the moment you go to bed, but from the moment you turn off your consciousness. We take this delay into account for accuracy.

Sleep calculator

Calculating the ideal time to wake up (in 90-minute cycles)

Close up time:

It will take: to fall asleep

Enter the time on the left
to calculate REM sleep stages

To get a good night's sleep, set your alarm for:

💡 Sleep consists of cycles of 1.5 hours. If you wake up between cycles (and not in the middle), you will feel alert even after a short nap.

Online sleep calculator

😴 How to wake up refreshed: the 90-minute rule

Did you sleep for 8 hours but woke up groggy? Most likely, the alarm went off during the deep sleep phase. Our sleep calculator solves this problem by calculating your ideal wake-up time based on your cycles.

🧠 The essence of the method: A person’s sleep is divided into cycles of 1.5 hours (90 minutes). It's easiest to wake upbetween cycleswhen the body is in the rapid eye movement (REM) sleep phase.

How to use the sleep calculator?

The tool works in two modes, depending on your purpose:

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I want to get up at... - indicate the time when you need to wake up, and we will tell you what time to go to bed.
I'll go to bed at... - specify the planned bedtime, and the service will calculate the best moments for waking up.

How much sleep do you need?

One cycle lasts approximately 90 minutes. For proper rest, an adult usually needs:

🔋 5 cycles: 7 hours 30 minutes (Gold Standard)
⚡ 6 cycles: 9 hours (For full recovery)
⚠️ 4 cycles: 6 hours (acceptable minimum)

Frequently asked questions (FAQ)

🔹 Is it possible to get enough sleep in 4 cycles (6 hours)?

Yes, this is possible in the short term. However, 6 hours is considered the lower limit of normal. If you sleep like this all the time, fatigue may accumulate.

🔹 Why do I wake up on my own 5 minutes before the alarm?

This is a great sign! This means your body clock is in sync with your sleep cycles. The body has completed the cycle and is ready for wakefulness naturally.

🔹 How is the time of falling asleep calculated?

It usually takes a person 10 to 20 minutes to fall asleep. In the calculator settings, you can specify your average time to fall asleep, and we will add it to the beginning of the first cycle for calculation accuracy.