How Long Do Babies Stay in Newborn Clothes (And What to Actually Buy)

One of the most common anxieties of new parenthood, alongside all the big, important ones, is the genuinely baffling question of baby clothes sizing. Everyone tells you they grow fast, but nobody tells you how fast, or what that means for the mountain of newborn gifts accumulating in your spare room. Here's an honest guide.

The Honest Answer: About 0-4 Weeks (Usually)

Most babies wear newborn clothes for somewhere between zero and four weeks. Yes, zero. Some babies, particularly those born above average weight, skip newborn size entirely and go straight into 0-3 months from day one. Others, particularly premature babies or smaller newborns, will wear their newborn for longer, sometimes up to 8 weeks.

The Sizing Timeline (Approximate)

• Newborn (NB): 0-4 weeks for average-sized babies, skip for larger babies, and up to 8 weeks for smaller babies

• 0-3 months: Typically worn from birth (for larger babies) or 4-8 weeks through to around 3 months

• 3-6 months: this is where you'll get the most wear

• 6-12 months: babies slow down a little in growth here

• 12-18 months: More variable depending on the individual baby

What to Actually Buy Before the Baby Arrives

• Newborn: 4-5 pieces maximum. That's enough for daily rotation for a few weeks while you figure out your baby's size.

• 0-3 months: This is your main investment. Buy 7-10 pieces across bodysuits, sleepers, and a few outfits.

• 3-6 months: 5-7 pieces, enough to have on hand without overstocking.

• Beyond: Wait until you know how fast your baby is growing.

Baby Gifting: The Secret That Experienced Parents Know

If you're buying a baby gift, size up. Always. A gift in 3-6 months or 6-12 months will be worn and appreciated, and the parents will think you're a genius. A gift for a newborn might be worn for two weeks, or not at all.

What to Look for in Baby Clothing

• Soft against newborn skin: no scratchy seams or labels

• Stretchy: 4-way stretch makes dressing a wriggly baby exponentially easier

• Breathable: babies can't regulate their temperature yet; breathable fabric helps

• Easy access for nappy changes: envelope necklines and snap closures at the bottom

• Hypoallergenic: newborn skin is sensitive; natural fibers are gentler than synthetics

Boody's Baby range ticks all of these: made from 95% bamboo viscose and 5% elastane, it's buttery soft, hypoallergenic, breathable, and has 4-way stretch. The range includes Romper, Long Sleeve Bodysuit, Long Sleeve Romper, Pants, Jersey Wrap, and Knotted Beanie.

SHOP ALL BABYWEAR

 

Frequently Asked Questions

Should I buy a newborn or 0-3 months size?

Buy a few newborn pieces and invest more in 0-3 months. If your baby is expected to be on the larger side, skip newborn entirely and start at 0-3 months.

How many newborn outfits do I need?

4-5 newborn outfits is plenty. Babies go through multiple outfits a day: you want a rotation, but not a wardrobe.

When do babies move to 0-3 months?

Babies move to 0-3 months usually somewhere between birth (for larger babies) and 4-6 weeks for average-sized babies.

What size baby clothes to buy as a gift?

As a gift, choose 3-6 months or 6-12 months baby clothes. You'll be the practical, appreciated gift-giver.