The Parents’ Sleep Index

May 21, 2008 | 21 comments

I was going to write something today, but unfortunately I find myself unable to put together a single coherent thought. My nine-month-old, who used to sleep through the night, seems to have decided that sleeping all night is for boring babies who are too dull to want to see what’s going on in the house from, say, 2:00 to 4:00 AM. My three-year-old also decided to wake up and scream for a while. He wasn’t scared or even upset. He was just screaming. For fun.

What I was marveling at this morning as I stumbled around my bedroom, too tired to remember how to find the bathroom, is how much more tired I feel when I am unexpectedly woken up. For some reason I function better when I’m regularly getting up with newborns than when I unexpectedly have to get up with older babies or children.

So, in lieu of whatever long-forgotten topic I was going to write about today, I present to you something I came up with at approximately 3:17 this morning: The Parents’ Sleep Index, a way to determine how many hours of sleep it feels like you got the night before.

Here is the formula:

t = total hours elapsed from time you got in bed at night until the time you got up for the day in the morning (i.e. amount of sleep you should have gotten)
e = number of children who woke up in the night
h = number of hours actually up with the baby and/or other children
a = baby’s age in months (for older children, age in years; if multiple children woke up, age of oldest child)
s = how surprised you were that you were woken up (scale of 1-10, 10 = most surprised)
w = number of times you had to get up
c = total number of children you have
y = number of hours of sleep you got the night before

It’s actually pretty accurate! (At least from my drowsy calculations while bouncing an overtired baby on my lap.) And, yes, you can get a negative number. There are definitely days where it feels like you somehow got negative sleep the night before.

Feel free to use this with any naysaying friends, family members, spouses, or bosses to prove how tired you are even if you technically got a reasonable amount of sleep the night before.

Meanwhile, I’m going to go count the seconds until nap time.


  1. Soul Pockets

    Sounds a lot like my bedtime routine!

  2. Anonymous

    Ingenious! I love this.


  3. Aimee

    Okay – it’s amazing to me that you can come up with a mathematical equation on so little sleep while I can’t even remember to brush my teeth!

    And I agree: getting up unexpectedly with an older child is MUCH harder than getting up with newborns. I think it’s mental conditioning. Newborns = no sleep whereas Older kids = expectation of good night’s rest.

  4. Barb

    Somehow you need to factor in the number of teenagers that are still in the home and think that being loud at 1:00am is not a big deal. Especially when the baby does not wake them up at 3:00am.

    Brilliant – planning to forward it to all the moms out there that I know!

  5. Whimsy

    In a few years you’ll be staying up to get quality time in with the adolescent, and then that child goes to bed for sleep you’ll be up a couple hours more with the toddler.

    Of course, by then you’ll be used to it, and will have been disabused of the indulgent notion that you actually deserve sleep.

  6. Jordana

    Those are such difficult days. I hope you got a nap today and that tonight will go better for you all.

  7. Kelly @ Love Well

    Equations at 3:17 AM?

    Without coffee?

    You need to factor in a brilliant mind. Surely, that can withstand the torture of sleep deprivation.

    And I agree — being woken unexpectedly from a deep sleep is the absolute worst. When that happens, I cannot shake the groggies.

  8. Anonymous

    I made a deal with my husband. Because I nursed the kids, only I got up with them for the first year or so. But after they weaned, they were his in the middle of the night for the rest of their lives.

    He thought he had such a deal – the first one has gotten him up maybe 4 times in his life. Then the second one weaned …

    I’m quite impressed with your formula. I’m lucky to be able to manage a rosary counting on my fingers when up in the middle of the night.


  9. Ginkgo100

    THIS is what you do when you’re too sleep deprived to function? AND figure out how to render the formula in HTML?

    May I present to you a Nerd Badge? Wear it with pride (like I do)! =)

  10. The Koala Bear Writer

    And I, as I bounce my 3-month old who is fussy because she hasn’t napped longer than 15 min. today, imagined that somehow it would get better as they get older. sigh. Going for naptime with her now that she’s asleep… again…

  11. RedSalamander

    I am laughing so hard at this. It’s funny because it’s true.

    It’s also true that you are completely deranged to come up with algebraic equations at 3 AM. However, I understand. I once spent an hour working out how to express mathematically why there is a constant amount of mess in my house which simply migrates from room to room. It tied in nicely with the theory of relativity and I probably would be winning some sort of Nobel prize right now if not for the fact that either the children or the pets ate the ragged post-it note it was written on.

  12. elizabeth

    There was a hysterical piece (or so I thought then) in the NY Times magazine years ago about the American phenomenon of lack of sleep and how we tout our tiredness as a badge of honor. The author mapped out this whole hierarchy about who in our society was the most tired and who deserved to crow loudest. Parents with small children won — they were “smug with exhaustion.” The argument was that we equate tiredness with importance (ie, if I have no time to sleep, I must be very important!). I now realize that there was NO WAY the author of that piece had children. There is no smugness in my complaints — or the complaints of my friends with children — about our bedtime struggles. I wish I had his phone number so I could call him, just for a chat, the next time my daughter decides 4:30 is “wake-up time.”

  13. Christine

    Hysterical! I have to link to this…

  14. matthew archbold

    Math? I’m too tired to do math! Must…get…through…day…

  15. Tienne

    Man, I love this! Like everyone else, I’m incredibly impressed you managed to come up with this at all, let alone on so little sleep.

  16. Eric and Wendy from Zoom

    We initially messed up the math and thought it was 20. After a dazed wondering of why we didn’t feel more rested, we recalculated. -4. That explains the math difficulties.

  17. Kristina

    Also, I think that when you get up matters. Any time in the first 3 hours blows my rest quotient.

  18. Missy @ It's Almost Naptime

    Wow, I can’t even do algrbra on a full nights sleep. Very impressive.

    I bet he’s teething. Mine wake up when they are teething – not crying usually, just playing.

    Here is my trick: put a bottle with some milk and some Motrin in his crib after he falls asleep – if you’re lucky, he’ll wake up in the middle of the night, swig it, and go right back to sleep.

  19. Laura

    This is terrific! I saw the link from Christine’s Fruit in Season, and I’m delighted to read this! 😉

  20. planty

    We had this all the time with our first and spend most of the first two years in a zombie like state everyday (Cafe Nero – a UK Starbucks clone – kept me going!)

    Then our second never did this, so we had a couple of years of getting back to normality.

    We’re onto number three now and back to the routine we experienced first time round!

    It doesn’t get easier, but I think I have learnt to consider the constant exhaustion the norm.

  21. Starrball

    I think there’s a few factors missing. It feels like you got more sleep when: you wake up for the day on your own and not because someone is crying, the phone rings etc… AND if when you wake up for the day after a long stretch of sleep (say 4 hours straight instead of the common 2)

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