bodysuit Babies: A Complete Guide to Making the Right Choice—What Size and What Material?

The babybodysuit is the most commonly worn item of clothing for infants—often several times a day. Simple in appearance, it actually comes in many variations: short- or long-sleeved, with snaps in the front or between the legs, made of organic or standard cotton, and in sizes that fit just right or run a bit large. This guide will help you choose the best baby bodysuits and build a well-rounded wardrobe starting at birth. 👶

🔍 The Different Types of Baby bodysuit

bodysuit with snaps between the legs (classic "bodysuit ")

This is the standard baby " bodysuit "—it fastens between the legs with snaps. Advantage: it stays securely in place and covers the tummy, preventing drafts. It can be put on over the head or through the neck. This is the most common style for babies aged 0 to 18 months.

bodysuit with snaps on the shoulder

The straps are positioned on the shoulders rather than around the neck, making it possible to put on and take off the bodysuit without having to pull it over the head. Ideal for newborns whose heads are still delicate, or for babies who don’t like having clothes pulled over their heads.

bodysuit kimono

It opens completely in the front like a kimono—no need to pull it over the head. The most practical solution for the first few days of life, when the baby is still very small and still has its umbilical cord. Ideal for the maternity ward.

bodysuit short sleeves, long sleeves, or sleeveless

• Sleeveless: for very hot days or as a base layer under a wetsuit
• Short sleeves: the versatile style, suitable for 8–9 months of the year
• Long-sleeved shirts: for fall and winter, often made of warm cotton or thermal fabric

📐 What size baby bodysuit should you choose?

bodysuit 's baby sizes generally follow this guide:

• Newborn / 50 cm: For babies weighing up to about 3.5 kg. Wear for 2–3 weeks maximum.
• 1 month / 56 cm: up to 4–5 kg. A few weeks.
• 3 months / 62 cm: the first “real” useful purchase. Fits 1–2 months.
• 6 months / 68 cm: 2–3 months.
• 9 months / 74 cm: 2–3 months.
• 12 months / 80 cm: 3–4 months.
• 18 months / 86 cm: the last " bodysuit " size for most children.

Tip: Don't buy too many newborn-sized items—babies grow very quickly. Focus your purchases on 3-month and 6-month sizes.

🧶 What material should you choose for a baby' bodysuit ?

OEKO-TEX-certified organic cotton

The go-to choice for infants’ delicate skin. The organic cotton is grown without pesticides or chemicals, and OEKO-TEX certification guarantees that the finished fabric is free of harmful substances. Soft, breathable, and hypoallergenic—it’s the top choice for babies with sensitive skin.

Interlock cotton

A knitted cotton fabric that is thicker and softer than classic jersey. It's very comfortable and retains heat well for the transitional seasons.

Bamboo

Ultra-soft, naturally temperature-regulating, and antibacterial. Excellent for babies who sweat a lot or have sensitive skin. Slightly more expensive but highly appreciated by parents.

Things to Avoid

Pure synthetics (polyester, acrylic) that don't breathe. Always check the fabric composition—a "soft" bodysuit may contain 30% polyester, which can cause irritation over time.

💡 How many baby onesies should you pack?

The question every parent asks themselves before the baby is born. Here's a realistic starting point:

• Newborn size: 3–4 onesies maximum — the baby will wear them for only a very short time
• Size 3 months: 7–8 onesies (frequent laundry, frequent accidents)
• Size 6 months: 6–7 onesies — the frequency of spit-ups decreases slightly
• Beyond that: 5–6 bodysuits per size are usually enough

Plan for a mix of 60% short-sleeved and 40% long-sleeved items, depending on the season the baby is born in.

🎨 Personalized baby " bodysuit ": an original gift idea

A baby bod bodysuit ed with the baby’s name printed or embroidered on it is one of the most appreciated baby gifts. It’s original, useful (unlike many baby gifts), and one-of-a-kind. You can find specialized online printers or bodysuits that can be customized directly.

For more ideas for unique baby gifts, check out our complete selection: 21 baby gift ideas that are sure to please.

🧺 How do you care for baby bodysuits?

• Wash at 30–40°C: this is sufficient to eliminate bacteria without damaging the fabric or the snaps
• No fabric softener: it can irritate your baby's skin and clog the breathable fibers of organic cotton
• Air-dry whenever possible: this preserves the elasticity of the ribbed edges and the softness of the fabric
• Ironing: Not necessary for cotton jersey—it stretches out on its own when worn by a baby

❓ FAQ — Baby bodysuit

Should you wear a bodysuit under your wetsuit?

Generally speaking, yes— bodysuit s protect the skin from the suit’s seams and zippers and serve as a base layer that regulates body temperature. In the summer, when it’s very hot, the suit alone (or even just the base layer) may be enough.

How do you put on a " bodysuit " without pulling it over your head?

The necklines on baby bodysuits are designed to widen thanks to the shoulder straps. The neckline of the bodysuit folds forward and downward, allowing you to remove it by sliding it down rather than pulling it up over the head—which is useful if stool has gotten on the back, to avoid getting the face even dirtier.

At what age should you stop using baby bodysuit ?

Most babies wear onesies until they’re 18–24 months old, and sometimes up to age 3 for long-sleeved styles. After that, children usually switch to regular T-shirts and tops. The bodysuit remains practical as long as the baby is in diapers—it stays in place well and prevents the garment from riding up.

bodysuit Babies: Should you use metal or plastic snaps?

Metal snaps are more durable and hold up better to repeated washing. Make sure they are treated to prevent rust and that they do not contain nickel (a potential allergen). Plastic snaps are lighter but may wear out more quickly.

🛍️ Baby bodysuits at PetitMaxou

Short-sleeved, long-sleeved, or sleeveless onesies made of soft cotton— PetitMaxou offers a selection of practical and comfortable onesies for your baby’s first few months. Available in a variety of colors and sizes. Free shipping throughout the EU.

→ See all baby bodysuits PetitMaxou

♻️ Baby bodysuit : Sustainable and Eco-Friendly

Baby clothes are worn for only a short time but bought in large quantities. Here are a few ideas for a more sustainable approach:

• Buy certified organic cotton: fewer pesticides, better for your skin and the environment
• Choose quality over quantity: 5 good-quality onesies are better than 10 low-quality ones that start to pill after 3 washes
• Resell or donate: Well-maintained onesies can be used for 2–3 children. Secondhand marketplaces dedicated to baby clothes have grown in popularity in recent years.
• Choose adjustable styles: Some onesies have extra buttons that allow you to “extend” the garment by one size.

To dress your baby smartly from head to toe, check out our guide on how to dress your baby in the summer —including temperatures, fabrics, and summer wardrobe essentials.