Sizing Methodology

For whatever reason, baby pregnancy trackers never seem to bother explaining how they come up with the objects used for comparisons. Babysizer feels that it's important that it be explained to you, in order for you to better visualize the size of your baby.

All comparisons on Babysizer are based on average fetal crown (top of the head) to rump (bottom of bum) length (CRL). Other pregnancy sites typically measure babies from crown to heel (CHL) instead of crown to rump beginning around week 20 or week 21 of pregnancy. This makes things ultra confusing as one week you are picturing your cute little one all curled up in the fetal position, but the next week you're expected to imagine your baby standing up straight as a stick. That's a little awkward, isn't it? Not to mention if you weren't aware of the change and you just look at the measurements during the switchover, it's as if your baby had a ridiculous growth spurt.

Babysizer specifically uses CRL as it better represents the size of your baby inside the womb for the entire pregnancy, making it much easier to visualize the size of your baby.

Objects were selected and assigned to a week using the longest side of the object. Short of every week being represented by a very large set of Russian nesting doll, there just aren't enough objects that are bigger in every dimension, week after week. The reality is that you may find that one week an object is wider or flatter than the next, or it differs slightly in size from another theme's in the same week. This is where you'll have to use a little imagination to fill in the gaps.

Some minor liberties were taken in assigning objects to weeks to ensure that each week could be represented by a relatable object. Babysizer has taken as much care as possible to select objects that are the same length as the average baby size each of the pregnancy week.

Every pregnancy is different, and babies grow at different rates. While Babysizer strives to be as factually accurate as possible, Babysizer should be used for entertainment purposes only. None of the information here should be considered as medical advice. If you have any concerns about your pregnancy, you should contact a medical professional.