Here’s an average duration of each sleep phase for an average person:
NREM-1: 5-10 minutes
This sleep phase occurs when you go to sleep. It’s the transition from being awake, to being asleep. It feels like you are in a trance. During this phase, you will normally lose consciousness, as the HI will distract you. In this phase, you may suddenly wake up. You will feel a falling sensation, then you feel a shock and open your eyes immedeately. It’s called a hypnic jerk. They are frequent when you are stressed or exhausted.
NREM-2: 5-10 minutes
A phase of very light sleep. It happens after NREM-1. During this phase, any sounds, light flashes, movements will easily wake you up. This phase relaxes your body and prepares you for the deep phase. Dreams and hallucinations are very rare. During this phase, we are usually unconscious.
NREM-3: 30-60 minutes
This is the deepest and the longest phase. During this phase, we regain the energy which we lost during the day. If a person is in this sleep phase, it’s very hard to wake him up. If you manage to wake him up, he will feel very groggy. It’s the worst time to wake up, as later in the day you may experience headache and other symptoms of tiredness. During this phase, dreams are more common compared to other NREM phases. Still, they happen rarely. As our body is not paralysed during this sleep phase, we may move during a NREM-3 dream. The worst that can happen, is that you fall out of your bed
REM-sleep: 5-60 minutes
It’s a pretty light sleep phase, where we experience dreams. Our body is paralysed during this sleep phase. If we wake up in the middle of this phase and fall asleep again, the REM phase will continue. Therefore, it’s good to do techniques like WILD here.
All these phases repeat a few times during the whole night sleep. Here’s a picture for you: