I was wondering how long each sleep stage is, and how long does it take to get to each stage from the moment you lie down. I’ve been looking, trying to find the answer, I guess I’m not looking the right places. If someone already knows then go ahead and tell me. 
Each sleep stage is lik 15-20 minutes i think, which are the first non-REM stages, then the REM which is like 5-10 minutes? and each time the whole stages complete it increases…
Okay thank you.
The stages of sleep wane through out the night. The longer you sleep the shorter they become.
stage 1 = 5-10mins
Stage 2 = 20mins
Stage 3 & 4 (delta sleep) = 10-30
Stage 5 (REM) = 10mins but will increase through out the night to up to an hour.
google and wikipedia are your friends
from what I’ve read its up to 90 minutes not an hour