Size Matters

By August 4, 2018Tools

Does Baby Size Matter?

You know that your baby’s growth is important. It’s a sign of general health, which is why it’s monitored by nurses and doctors. Growth that is too fast or too slow can be a sign of health problems.

The value of tracking growth is widely accepted. But what should you measure? How should you measure?

The Big 3 of Size

There are many possible aspects of growth to measure. Three are basic: Weight, length, and head circumference. The World Health Organization uses these core features of baby size worldwide.


Weight is the feature of growth we think of first. Other than gender, a baby’s weight may be the most mentioned feature of a newborn. Scales are common, so weight is the most widely used size measurement.


Length is also familiar. It’s similar to height, but babies can’t stand. For this reason, infants and toddlers under 2 years are measured while they are lying down. Length is the distance from the top of the head to the soles of the feet. It is more difficult to measure than weight. Babies squirm and avoid straightening their legs.

Head Circumference

Head circumference is the baby’s hat size, the distance around the skull. It’s less familiar as an aspect of size. It’s important because the brain grows most in size before two years. The brain is covered by the skull, so the size of the skull reflects brain growth.

Measurement DIY

You can measure each of the Big 3. Want to know how? You will need the help of another adult and some household items. For details, follow these links for each of the Big 3: