Baby nap math calculator in Google Sheets

, a 2 min read

I don’t know about anyone else, but I never had to think so much about schedules before having a baby. The only times I needed to pay attention to were meetings and events. And if it wasn’t on my calendar, it simply didn’t exist!

But for the first 6 months of my baby’s life, my life revolved around her sleep schedule.

The truth is that babies are a lot like grownups. They don’t sleep if they aren’t tired. The big difference is that babies will be very very angry if they’re expected to sleep and they’re not tired. And they can also get very very angry if they get too tired!

You see the quandary here? Woe to those who get their baby’s wake windows wrong!

There’s also a balance to strike with how much they nap during the day, and how much you expect them to sleep at night.

To get any semblance of predictability, you start to track when your baby wakes up, how long they sleep, and when the next nap should start. It’s a lot to do in your head, and I eventually got tired of it.

So I made a tool in Google Sheets to do the calculations for me!

What you need

  • A Google account, although you could also download this on Excel or Numbers if you really wanted. The bonus of using this on Google Sheets is that you could download the app and edit/refer to this on the go!
  • The ability to enter times in HH:MM format

That’s it!

The calculator

Click around the nap math calculator or make a copy in Google Sheets

Instructions

  1. Enter the wake windows you want to try in column D, in HH:MM format. I recommend suggestions from the book Precious Little Sleep—not sponsored, just a huge fan!
  2. Every morning, enter your baby’s wake time in cell B2, and night sleep time in cell E10.
  3. Follow the suggested start times for naps. As you progress through the day, update the nap lengths in column E, in HH:MM format
  4. When you drop a nap, zero out the values for wake windows and nap lengths in that nap row. You can then hide the rows.

Adjusting wake windows

Using the calculator makes it easy to track anything you want to change, especially wake windows.

From Precious Little Sleep, the general idea is that if your baby is waking in the middle of the night, you need to cut down on day sleep. And if they’re crying for more than 20 minutes at the start of the nap, it’s time to extend wake windows.

Though, keep in mind that timing is only one reason why your baby is not sleeping. All bets are off they aren’t already sleeping on their own, and if they’re still feeding at night. (It’s a big reason why I chose to sleep-train my baby. If she cried, I knew it was due to illness or needing a schedule change. Or she unzipped her sleep sack, haha.)

But having a good schedule is also a prerequisite if you do want to sleep-train your baby. After all, babies who are not tired don’t sleep. 😉 It’s a lot of experimentation, and every sleep is an opportunity to practice.

Graduating from doing nap math

It depends on your baby, but I found I didn’t need this calculator anymore after my baby went to 2 naps. The wake windows simply didn’t matter as much for her sleep experience. And then I was free from nap math forever!