Baby Clothing Sizes Australia: Full Size Chart
Australian baby clothing sizes run 00000, 0000, 000, 00, 0, then 1, 2, 3 and up to 8. The zeros count backwards from birth, and once a child passes about two years old the numbers count forward in years. That is the whole system in two sentences, and it is the part nobody explains on the label.
The practical version: 0000 is newborn, 000 is 0-3 months, 00 is 3-6 months, 0 is 6-12 months, 1 is 12-18 months and 2 is 18-24 months. From size 3 the number is roughly the child's age in years. "Newborn" and "0-3 months" are not the same size, which is the most common mix-up when parents buy their first bundle.
This guide covers the full range, 0-3 months through size 8, with weight ranges, AU to European and American conversions, and how to buy ahead without filling a drawer with clothes your child never wears. For bodysuits specifically, our guide to baby onesies and bodysuits goes deeper on types, quantities and features.
Australian baby size chart: 00000 to size 2
Baby sizing in Australia and New Zealand is driven mainly by weight, not age. Two babies the same age can be two sizes apart.
AU/NZ size |
Age guide |
Weight guide |
Height guide |
00000 |
Premature |
Up to 2.5 kg |
Up to 48 cm |
0000 |
Newborn |
Up to 4 kg |
48-56 cm |
000 |
0-3 months |
4-6 kg |
56-62 cm |
00 |
3-6 months |
6-8 kg |
62-68 cm |
0 |
6-12 months |
8-10 kg |
68-76 cm |
1 |
12-18 months |
10-12 kg |
76-86 cm |
2 |
18-24 months |
12-14 kg |
86-92 cm |
Height ranges are a guide only and vary between brands. If your baby sits between two sizes, size up. A tight bodysuit restricts movement and gets outgrown in a fortnight.
The World Health Organization publishes weight-for-age growth standards showing how wide the normal range is at every month. A healthy six month old can sit anywhere from about 6 kg to 10 kg, which spans three clothing sizes. That is why the age label on the tag is the least useful number on it.
Kids clothing sizes in Australia: size 3 to size 8
Once a child hits about two the system flips. The number on the tag becomes their approximate age in years, and height takes over from weight as the better fit signal.
AU/NZ size |
Age guide |
Height guide |
3 |
2-3 years |
92-98 cm |
4 |
4 years |
98-104 cm |
5 |
5 years |
104-110 cm |
6 |
6 years |
110-116 cm |
7 |
7 years |
116-122 cm |
8 |
8 years |
122-128 cm |
From size 3 onwards, measure your child's height against a wall and use that. By school age the height spread within a single year group is wide, and plenty of five year olds are comfortably in a size 6.
Yes Mila runs 0-3 months through size 8. On our product pages the sizes are labelled 0-3M, 3-6M, 6-12M, 1Y, and 2Y to 8Y rather than 000, 00 and 0, so match the month range rather than looking for a zero count. Browse girls 2-8 or boys 2-8 for the older end of the range.
Why the numbers go down, then up
The Australian system is two systems stitched together. The zeros are a countdown to birth. Size 1 is the baseline, roughly a one year old. Everything smaller gets an extra zero: 0 for the second half of the first year, 00 for three to six months, 000 for the first three months, 0000 for newborns and 00000 for premature babies. More zeros means smaller.
From size 1 upward the numbers simply track years. It is an old convention rather than a designed one, which is why it feels backwards the first time you see it.
AU vs EU vs US sizing conversions
Yes Mila's pieces are designed in Europe, so European conventions are relevant here. European brands size by height in centimetres, the most precise of the three systems. American brands size by month range, the loosest.
AU/NZ |
EU (cm) |
US |
Age guide |
0000 |
50-56 |
Newborn |
Newborn |
000 |
56-62 |
0-3M |
0-3 months |
00 |
62-68 |
3-6M |
3-6 months |
0 |
68-76 |
6-12M |
6-12 months |
1 |
76-86 |
12-18M |
12-18 months |
2 |
86-92 |
18-24M / 2T |
18-24 months |
3 |
92-98 |
3T |
2-3 years |
4 |
98-104 |
4T |
4 years |
5 |
104-110 |
5 |
5 years |
6 |
110-116 |
6 |
6 years |
7 |
116-122 |
7 |
7 years |
8 |
122-128 |
8 |
8 years |
Two things worth knowing. European sizes are the child's height, so a EU 74 fits a child who is 74 cm tall. And American toddler sizes carry a T (2T, 3T, 4T), cut for a nappy-wearing shape, while the plain numbers (4, 5, 6) are cut slimmer. If you are ordering from a US brand, 4T and 4 are not the same garment.
How long each baby size actually lasts
This is where money gets wasted.
00000 and 0000 are short-lived. Most babies wear 0000 for three to six weeks, and babies born over about 3.8 kg may skip it entirely. Buy a handful, not a wardrobe.
000 covers roughly two to three months. It is the first size that gets real wear.
00 and 0 each tend to last around three months, sometimes longer through the 6-12 month band as growth slows.
Size 1 and up stretch out. A size 2 can be worn for six to nine months, and by size 5 or 6 a well-cut piece can last a year.
The first year burns through sizes and everything after that slows down. Spend lightly at the bottom of the range and invest in the sizes that stay in rotation.
How to buy ahead sensibly
Buying ahead saves money in a sale, but only if you get the season right.
Work out the month, not just the size. If your baby is in 000 in August and you buy a size 0 to grow into, that size 0 gets worn from around December through autumn. Buy summer weight, not a coat.
Buy one size ahead, not three. Growth rates are unpredictable enough that two years out is guesswork.
Check your baby's most recent weight from their child health record (the blue book in NSW) or last health check and use the weight column, not the age column.
Keep the basics generous and the outfits precise. Bodysuits, leggings and sleepwear can run slightly large without looking wrong. Dresses and jackets look better bought to fit.
Fit signals to look for
Sleeves covering the fingers with room to spare, a crotch sitting well below where it should, or a gaping neckline all mean the piece is too big rather than pleasantly roomy.
Red marks around the leg openings, a bodysuit that pops open at the crotch, or trouser cuffs riding above the ankle bone mean it is time to move up.
For sleepwear, fit matters for safety as well as comfort. Red Nose Australia advises dressing baby appropriately for the room temperature, not over or under dressed, with their head and face uncovered. A sleeping bag should be fitted around the neck and have armholes, and wraps should be lightweight muslin or cotton.
Where Yes Mila sits
Yes Mila's baby range starts at 0-3 months (000) and runs to size 2, with the broader range going through to size 8. The pieces are designed in Europe and made to hold their shape wash after wash, which matters when one bodysuit gets worn twice a week for three months.
Start with baby essentials for the pieces that do the heavy lifting in the first year, or browse the full baby range for 0-2. Common sizing questions are answered on our FAQs page. Free shipping across Australia on orders over $100.
Frequently Asked Questions
Is newborn the same as 0-3 months?
No. Newborn is size 0000 and fits babies up to about 4 kg. 0-3 months is size 000 and fits 4-6 kg. They are one full size apart. A 4 kg newborn sits at the very top of 0000 and moves into 000 within a couple of weeks.
What size is a 6 month old baby in Australia?
Most six month olds are in size 00 (3-6 months) or size 0 (6-12 months) depending on weight. Over about 8 kg, go to size 0.
What does 000 mean in baby clothes?
Size 000 is the Australian and New Zealand size for 0-3 months, fitting babies roughly 4-6 kg and 56-62 cm tall. Each additional zero means one size smaller, so 0000 is newborn and 00000 is premature.
How do Australian sizes compare to European sizes?
European sizes are stated in centimetres of height. AU 000 is roughly EU 56-62, AU 0 is roughly EU 68-76, AU 2 is roughly EU 86-92. Measuring your child's height gives a direct conversion.
Should I size up in baby clothes?
Yes, if your baby is between sizes. A slightly loose fit is comfortable and lasts longer. The exception is a sleeping bag, which should fit at the neck and have armholes so it cannot ride up.
What size should I buy as a baby gift?
Size 000 or 00 rather than 0000. Newborn size is usually already covered and outgrown in three to six weeks. A 0-3 or 3-6 month piece gets worn properly.
Browse the full Yes Mila range, 0-3 months through size 8.
