I have tracked my time continuously since April of 2015. As long time readers know, those years have featured a lot of changes in my life. But one thing has been constant: I average somewhere between 7.3-7.4 hours of sleep per day.
That’s how much I slept, on average, from April 2015-April 2016, the first full year I tracked. It’s also how much I averaged during 2024, which is the last full year I’ve analyzed.
What’s crazy about that is that in April of 2015, I had a three-month-old baby. In 2024, all my kids were school-aged. During both years there were various bad nights (waking baby, early flight) or longer nights (sleeping in, crashing). Yet it still came out to the same amount.
One way or another, over any period of 8 weeks or so, my average will be a number between 7.3 and 7.4 hours. Clearly, I am dealing with a strong orientation toward that amount. I could wish that number were different, and sometimes I have, but I’ve learned that I’m probably best off accepting it rather than trying to change it — since it doesn’t look like I can change it even if I tried.
A different view of sleep deprivation
From studying thousands of people’s time logs, I’ve seen that many people have a similarly strong set point. This isn’t the case with chronic insomniacs, but for lots of us, what we think of as “sleep deprivation” doesn’t show up in total sleep hours for longer chunks of time. Instead, what’s happening is that we undershoot on certain days in ways that make us miserable, and then we crash on other days — but tend not to count the crashing in our mental models. Someone who sleeps 6 hours a night Sunday through Thursday, and 12 hours a night Friday and Saturday, is getting 54 hours a week, and averaging 7.7 hours of sleep per day, which is reasonable. But this person is certainly going to feel sleep deprived by late in the work week, and is also probably going to say they sleep 6 hours a night (the mode) even though the average (the mean) is quite different.
Sometimes people claim they’re too busy to sleep, but if you subscribe to the set point theory, then skimping some nights isn’t actually saving time. You’re just redistributing sleep — generally toward weekends or by crashing on the couch at night. Personally I’d like to be awake to enjoy my evenings and weekends!
What can’t be changed
We can wish we only needed 6 hours of sleep. But very few people do. Sometimes people get upset about this. They particularly get upset if they realize they actually do need 8 hours of sleep, or even 8.5, which is normal. The difference between needing 7.4 hours and 8.4 hours is (obviously) an extra hour in the day to work, relax, do hobbies, etc. When I feel upset about needing 7.3-7.4 hours, I remind myself that the number could be a lot higher!
But if it is toward the upper range for you, and you do have more sleep needs, instead of fretting about something you probably can’t change, it might be better to remind yourself that most people with lower sleep needs don’t use this extra time well. Someone who uses 16 hours a day well is going to get more out of life than someone who uses 17 hours unintentionally.
And the upside of figuring out exactly how much sleep your body is aiming for (as in, your long term average) is that you can then structure your life to get this amount most nights. This will allow you to use the time you do have even better. You’ll be able to take each day as it comes rather than building up a sleep debt that keeps you from having adventures on the weekend.
If you don’t know how much sleep you need, try starting with 7.5 hours and seeing how that goes. Count back 7.5 hours from when you need to wake up during the week and make sure you are in your bed with the lights out a few minutes before then. If you get to the weekend and still feel exhausted, maybe you need a little more. Go for 7.75 and see how that works. If you aim for 7.5 hours and find yourself consistently waking up before your alarm then you might need less.
But there’s no point acting like there isn’t a number your body is aiming for. Most of us can’t actually train ourselves to get by on less sleep. By respecting the fact that you need the sleep you need, you can feel better and make more mindful choices with whatever waking hours you do have.
This is such a good mantra, honestly. I'm a higher sleep need person and so is one of my kids. She's so frustrated that she can't go to bed at 11pm and get up easily at 6:30 because she needs roughly 9 hours. Unfortunately it's a lesson she has to learn herself even though I know what the obvious solution is. I'm solidly 8.5 hrs if I've been getting good sleep regularly but 9+ if not. It sucks but there's no other way to fix it besides sleeping the right amount.
It's normal for me to wake up and go back to sleep a few times. Over the last year I've done an experiment a handful of times on a weekend day. I allowed myself to sleep until I woke up and couldn't go back to sleep. Every time I've done this it's been right around 9 hours. But that's about as far as I've gotten. I haven't been disciplined enough to try for 9 hours on weekdays.