How Many Baby Clothes Do You Need in Each Size? A Newborn Clothing Checklist

The honest version: buy less newborn than you think, and more of the next size up.

Baby clothing sizing trips up a lot of first-time parents, mostly because it's easy to assume "newborn" means the first few months, when really it can mean the first few weeks. Overbuying the smallest size and underbuying the one that actually gets worn is one of the most common and avoidable baby-prep mistakes.

Understanding Australian Baby Clothing Sizes

Australian baby clothing sizing runs roughly like this, though it varies a little between brands, so treat it as a general guide rather than an exact rule:

• 0000 (Newborn): up to about 4kg and 56cm, often only the first few weeks

• 000: roughly 0 to 3 months

• 00: roughly 3 to 6 months

• 0: roughly 6 to 12 months

• 1: roughly 12 to 18 months

Weight is a better guide than age if your baby runs larger or smaller than average, or arrives early. Check the weight range on the label rather than relying on the age range alone.

The Checklist by Size

0000 (Newborn)

Buy light here. Plenty of babies, especially bigger ones, are out of this size within two to four weeks.

• 4 to 6 bodysuits (singlets or short-sleeve, depending on climate)

• 4 to 6 sleepsuits or rompers

• 2 to 3 cardigans or jackets, depending on season

• 1 to 2 swaddles or wraps for the early weeks

• 4 to 6 pairs of socks or mittens (these vanish constantly, buy more than feels necessary)

• 1 to 2 soft hats

000 (0 to 3 Months)

This is usually the size worth stocking up on, babies tend to live in it for a genuine stretch of time.

• 6 to 8 bodysuits

• 6 to 8 sleepsuits or rompers

• 2 to 3 cardigans or jackets

• 4 to 6 pairs of socks

• 2 to 3 outfits for outings, if that's something you want beyond everyday basics

00 (3 to 6 Months)

Growth often eases a little after the first few months, but babies still tend to spend a good while in this size, so similar quantities to 000 are a reasonable starting point.

• 6 to 8 bodysuits

• 6 to 8 outfits or sets (two-piece sets get handier once babies start rolling and wriggling)

• 2 cardigans or jackets

• 4 pairs of socks

What to Buy More of, and What to Hold Off On

• Buy fewer newborn-size items and more of the next size up, it's rare to regret having extra 000 on hand, and common to regret a drawer full of barely-worn newborn clothes.

• Bodysuits and sleepsuits get the most wear by far, prioritise these over occasion outfits in every size.

• Accept hand-me-downs and gifts gratefully before buying ahead yourself, they fill gaps in sizes you can't predict you'll need yet.

• Hold off on buying much in sizes beyond 00 until you have a better sense of how quickly your baby is growing.

Sleepwear and Sleep Sack Sizing

Sleepwear runs on a slightly different track to daytime clothing, since it's chosen by weight and room temperature rather than age alone. Sleepybelly's Newborn Swaddle Sack covers the 0 to 3 month, 3 to 6kg stage, with an arms-in or arms-out design for the transition out of swaddling. From there, the Infant Sleep Sack covers 3 to 12 months (roughly 6 to 12kg), so between them the two cover the whole first year.

If you're unsure what to actually dress your baby in underneath either one, our Australian TOG and temperature guide breaks it down by room temperature, and our comparison of swaddle sacks versus wraps is worth a read if you haven't settled on a swaddling method yet.

Frequently Asked Questions

1. How many newborn outfits do I actually need?
   Fewer than most checklists suggest, somewhere around 4 to 6 bodysuits and sleepsuits is usually plenty, since many babies move into the next size within a few weeks.

2. Should I buy ahead in bigger sizes before my baby needs them?
   A little, but not too much. It's hard to predict exactly how fast a baby will grow, so buying one or two bigger-size items as a backup is reasonable, while holding off on stocking up fully until you see the growth pattern.

3. Is it safe to use second-hand or hand-me-down baby clothes?
   Generally yes, clothing itself doesn't carry the same safety considerations as things like car seats or cots. A wash before first wear is a sensible habit regardless of where an item came from. For anything your baby will sleep in, skip items with hoods, cords or ties, and check buttons and press studs are still secure.

4. What if my baby is born early or smaller than average?
   Weight is the more reliable guide in this case rather than the age ranges on the label. Premmie or newborn-size clothing with a lower weight range may fit for longer than the "typical" timeline suggests.

5. When should I move from a swaddle to a sleep sack?
   Once your baby shows signs of rolling, Red Nose advises stopping wrapping, or once they reach 4-6 months, whichever comes first. That's why the Newborn Swaddle Sack converts to arms-out. Sizing-wise, it lines up neatly with moving from a 0 to 3 month swaddle into a sleep sack sized for 3 months and up.

These quantities are a starting point, not a strict rule. Every baby grows at a different rate, so adjust freely based on how quickly yours moves through each size.

The information in this article is general in nature and intended as comfort support only. It is not medical advice. Always consult your midwife, GP, or a qualified healthcare provider for guidance specific to your situation.