Understanding Premature Baby Clothing Sizes

If your baby has arrived earlier than expected, choosing clothing can suddenly feel confusing and emotional. Many families tell us they hadn’t even thought about premature sizing before their baby was born — so please know you’re not alone, and it’s completely okay to need extra guidance.

In Australia, premature baby clothing sizes can vary between brands, which can make things harder when you’re already navigating a lot. Some labels use 00000 (five-zero) to describe very tiny newborn sizes, while others may use XXS for garments designed specifically for premature babies or those with a lower birth weight. You may also see PM or “Preemie” sizing on UK or US brands.

Most premature clothing is generally designed for babies with a birth weight under around 3kg, but the actual fit, length, and room for growth can differ quite a bit depending on the purpose, design, brand and style.

Because there isn’t one universal sizing standard, a size that works beautifully in one label may feel quite different in another. This is why choosing soft, breathable fabrics, gentle seams, and easy-to-dress designs — along with the right size — can make such a difference to your baby’s comfort and warmth during those early days.

At Kids of Eltham, we truly understand how important and sometimes overwhelming this stage can feel. Our caring, experienced team is here to help you find practical, comfortable premature baby clothing that supports your baby’s needs while allowing for growth and medical care if required.

If you'd like personalised fitting advice, pop in and visit us in-store, or, give us a call (03) 9439 5700 if you need guidance before you shop online. We’re always here to support families with caring, practical advice during those precious early days.