Quick answer: our baby clothes are sized by age in months: 0-3, 3-6, 6-9, 9-12, 12-18 and 18-24 months. One vest pack starts smaller, at Newborn and 1-3 months. Pick the size band your baby is in now. If your baby is near the top of that band, or between two sizes, the bigger size will usually fit for longer.
Age sizes are a starting point, not a rule. Two babies of the same age can wear different sizes, so the clothes that fit your baby today are your best guide. This page lists exactly which sizes each piece in our kidswear collection comes in, and how to choose when you are unsure.
What sizes do your baby clothes come in?
These are the sizes each product is offered in, as listed in our store today:
| Product | Sizes offered |
|---|---|
| Pastelpops Front Open Vest, Pack of 3 | Newborn, 1-3, 3-6, 6-9, 9-12 months |
| Drop Needle Full Sleeve Onesie, Aqua Foam | 0-3, 3-6, 6-9, 9-12, 12-18 months |
| Drop Needle Full Sleeve Top and Bottom Set, Baked Clay | 0-3, 3-6, 6-9, 9-12, 12-18, 18-24 months |
| Drop Needle Ruffled Top and Bottom Set, Veiled Pink | 0-3, 3-6, 6-9, 9-12, 12-18, 18-24 months |
| Drop Needle Half Sleeve Polo T-Shirt, Ballad Blue | 0-3, 3-6, 6-9, 9-12, 12-18, 18-24 months |
| 100% Crinkle Cotton Diaper Pant, Off White | 0-3, 3-6, 6-9, 9-12, 12-18, 18-24 months |
| Mushmellow Off White Pointelle Top and Bottom Set | 0-3, 3-6, 6-9, 9-12, 12-18, 18-24 months |
| Mushmellow Peach Dust Pointelle T-Shirt and Bottom Set | 0-3, 3-6, 6-9, 9-12, 12-18, 18-24 months |
Two things to notice. The onesie stops at 12-18 months, even though its name says 0-2 years, so for an older toddler choose one of the sets instead. And the vest pack is the only piece with a Newborn size.
Do you have a size chart in centimetres?
Not yet. Our product listings give sizes by age only. They do not list chest, length or height measurements, so we do not publish a centimetre chart here rather than guess one. If you need a measurement for a particular piece, ask R for Rabbit's customer care before you order.
How do I choose between two sizes?
Start from what fits your baby now, then use these checks:
- Your baby is near the top of a band. For example, a five month old in 3-6 months. Go one size up, so the piece fits for more than a few weeks.
- Your baby's current clothes feel snug. Choose the bigger size, especially for full sleeve sets and onesies.
- Room for a diaper. Several of our pieces are described as "diaper-friendly": the diaper pant, the onesie, both Mushmellow sets and the Baked Clay set.
- Stretch helps. The drop needle pieces are described as having "a gentle stretch", and the Baked Clay and both Mushmellow sets have elastic waistbands, which can give a little extra room.
- Buying a gift? Choose a size ahead of the baby's current age, so it still fits by the time it is worn.
Which styles suit which age?
Newborn to 3 months
The Pastelpops vest pack is made for the first weeks. Its listing says the front button opening "means dressing your newborn without pulling anything over their head", and that it is 100% cotton crinkled muslin. Browse more in our Newborn ready collection.
3 to 12 months
The Aqua Foam onesie has a Henley neck opening that, its listing says, "makes dressing simple", with rust-free snap buttons. The two Mushmellow sets are knitted in 100% cotton pointelle, and the Off White set has raglan sleeves for "crawling, climbing, and everything after". Browse everything for 6 to 12 months.
12 to 24 months
For toddlers, the sets, the Ballad Blue polo (with wooden buttons, its listing says) and the diaper pant all go up to 18-24 months. Browse everything for 1 to 2 years.
How should I dress my baby in hot weather?
Lightly. Overheating is a real risk for babies, especially during sleep. The Lullaby Trust, a UK safer sleep charity, says the risk of sudden infant death syndrome (SIDS) "is higher in babies who get too hot". Its advice for warm days:
- "In hot weather, it's fine to have your baby in a lightweight layer such as a short sleeve bodysuit, or even just a nappy."
- To check if your baby is too hot, feel their chest or the back of their neck. Their hands and feet are usually cooler, which is normal. If their skin is hot or sweaty, remove a layer.
- Take hats off indoors, because babies lose heat through their heads.
Light, breathable fabrics help here. Our listings describe the drop needle rib as "breathable" and "moisture absorbent", and the vest pack's muslin as "light, airy". If you use a stroller on hot days, our stroller guide explains why you should never cover it with a cloth.
What are the fabrics and finishes?
Each listing describes the same finish: AZO-free dyes, a pH-balanced finish, fabric or trims with no harmful metals, and a colourfast finish with no pilling. Wash care is not listed on these product pages, so check the label on the garment or ask R for Rabbit's customer care how to wash it.
Questions parents ask
What size should I buy for a newborn?
Newborn or 0-3 months. Our Pastelpops vest pack is the only piece with a Newborn size; every other piece starts at 0-3 months.
Should I size up for my baby?
If your baby is near the top of their age band or between sizes, yes. The bigger size will fit for longer, and several of our sets have elastic waistbands.
What does 12-18 months mean on a label?
It is the age band the size is made for, from 12 months up to 18 months. Use it as a starting point and compare with what fits your baby now.
Is there a centimetre size chart?
No. Our listings give sizes by age only, so ask R for Rabbit's customer care if you need a measurement for a specific piece.
More guides: baby sippers and cups, when is a baby ready for a high chair, and all our parent guides.
Sources
- The Lullaby Trust, "Dress your baby for sleep" (overheating and SIDS, hot weather clothing, checking temperature, hats indoors): lullabytrust.org.uk/baby-safety/baby-product-information/dress-your-baby-for-sleep/
- The Lullaby Trust, "Hot weather" (lighter clothing, checking chest or back of neck; last reviewed 1 Feb 2025): lullabytrust.org.uk/baby-safety/travel-and-weather/hot-weather/
- R for Rabbit product listings for each piece named above (sizes offered, fabric and finish as stated there).