While some people think dreams last 7 seconds, that is a myth. In the following brief article I shall try to answer the question of how long dreams last.
While dreaming can occur in deep sleep and even while we’re wide awake, when most people say “dreams,” they refer to those vivid dreams we experience during REM sleep, short for Rapid Eye Movement sleep. It is called that because while the whole body is paralyzed during REM sleep, the eyes move in the direction our eyes look in the dream.
Thus, to answer the question of how long dreams last, we need to know how much REM sleep we experience every night.
During sleep, we go through cycles of 90 minutes. The ideal sleep includes 5-6 such cycles, making up a total of 7.5-9 hours. However, many of us settle with only 4 sleep cycles, and sometimes even less.
For the sake of our example, let’s go with a 7.5-hour night, which consists of 5 sleep cycles of 90 minutes each.
First, you enter the deeper stages of sleep, and then comes REM sleep, then again, deep sleep, REM sleep, cycle 2. Deep sleep, REM sleep, cycle 3, and so on and so forth.
In the first and second cycles deep sleep is longer while REM sleep is shorter, while in the later cycles REM sleep gets longer and longer, while deep sleep occurs less and less.
The duration of REM periods range from 5 minutes in the beginning of the night to 60 minutes toward the end.
As we grow older, we tend to spend less and less time in REM sleep, while newborns may spend up to 80% of their sleep dreaming.
The normal proportion of REM sleep is 20-25% of total sleep in adults.
So if we’re sleeping seven and a half hours per night, 1.5-2 hours may be spent in dreaming.
So in a 7.5-hour sleep, consisting of 5 cycles, that’s 18-24 minutes per cycle, or 20 minutes on average. But some cycles may be broken down into 2 dreams, or even more.
This leads to the conclusion that the average dream lasts approximately 10-20 minutes, but is often shorter in the beginning of the night and longer towards its end. Also, on average we may experience (or be unaware of) 5-10 dreams per night. Maybe the 7 second myth regarding the duration of dreams has resulted from a confusion with the number of dreams per night, which averages around 7 dreams.