Doctor’s offices are usually pretty high-tech places. Ultrasound machines, blood pressure machines on wheels… it seems like everything is digital these days. So it’s a surprise to see an old-school paper tool like the pregnancy wheel.

You might wonder: What’s that for? Let’s break it all down, including:

  • What is a pregnancy wheel?
  • Where to buy a pregnancy wheel online
  • Why a pregnancy wheel isn’t the gold standard anymore
  • Plus, more modern options

What Is a Pregnancy Wheel?

Health professionals use the pregnancy wheel to determine a baby’s due date.

It looks like something you might have used in a high school math class: two circular pieces of cardboard attached by a brad. The months and days of the year are on the outer wheel to calculate due dates. Plus, information on fertility, screenings, and your baby’s size are on the inner wheel.

How to Use a Pregnancy Wheel

Like most due date calculators, a pregnancy wheel uses your last menstrual period as a benchmark. A pregnancy wheel is an incredibly simple tool to track your pregnancy and baby’s progress. Here’s how to use it:

  • Find the arrow labeled “first day of last period” on the inner wheel and move it to point to that date.
  • Now all of the other important dates in pregnancy, from conception to hearing your baby’s heartbeat, to your due date, will align with the appropriate dates.

Where to Find a Pregnancy Wheel Online

If you think a pregnancy wheel is a helpful tool to have, they’re easy to find and buy online. You can find rather inexpensive models on Amazon and on midwife and nursing supply websites.

Why the Pregnancy Wheel Isn’t the Gold Standard Anymore

But let’s get real, who needs a laminated paper wheel when you can just download an app? Many of the apps on my list of the best pregnancy apps tell you everything you’d find on a pregnancy wheel, and more.

In general, there’s been a technological shift towards digital due date calculators, even by the American College of Obstetricians and Gynecologists.

“ACOG supports the use of the EDD Calculator and will transition away from the physical plastic wheel in favor of this modern reinvention.” (source)

Try the Mama Natural Due Date Calculator Instead

The Standard Due Date Calculator

Based off Naegele’s Rule, Mama Natural’s due date calculator assumes a pregnancy lasts 280 days. It calculates due dates off a regular, 28-day cycle, with ovulation occurring on day 14. This type of due date calculator is most widely accepted, because it is much easier for a woman to remember her last menstrual period than it is for her to pinpoint ovulation or conception.

The Advanced Due Date Calculator

But some women, especially those who have irregular or longer cycles, may need to calculate their due date differently. That’s why Mama Natural also has an advanced due date calculator. This due date calculator incorporates the length of your luteal phase, your height and weight, age, and lifestyle factors to get a more accurate due date.

As always, though, remember that a due date is more of a suggestion. Baby will arrive when baby wants to arrive.

If You Already Know Your Due Date…

What if you already know your due date? You might want to try a reverse due date calculator if you:

  • Had a dating ultrasound that provided your baby’s gestational age and due date.
  • Want to pinpoint the time of conception.

By inputting your due date you can calculate the window in which intercourse most likely led to conception.

It’s also a great tool if you want to try to time your baby’s birth. Want a September baby? Calculate backwards to determine when you need to conceive.