Updated October 2026
Baby and toddler sizing is one of those parenting puzzles nobody warns you about. One brand's 6 months fits like another brand's 3 months, and just when you figure it out, your little one hits a growth spurt. Here's everything in one place, from newborn to size 16.
The short version
- Go by height and weight first, age second.
- Between sizes? Size up.
- Using cloth diapers? Size up for room in the seat.
Baby and Toddler Size Chart by Age, Weight, and Height
Every brand cuts a little differently, so treat this as your starting point. For exact Bam & Stitch fit by style, use our pajama size chart.
Shop by size
Found your size? Shop soft bamboo pajamas.
Convertible RompersNewborn to 2T
Pajama Sets12 months to 16
New Holiday PrintsMerry Galaxy, Main Street Bears and Sunday Huddle
Between sizes? Go with the bigger one.
Baby and Toddler Sizes: Quick Answers
What size does a 1 year old wear?
Most 1 year olds wear 12 to 18 months, which fits about 22 to 26 lbs and 29 to 32 inches. A smaller 1 year old may still be in 6 to 12 months, and a tall one may be ready for 18 to 24 months. Go by weight and height, not the birthday. Shop convertible rompers in 12 to 18 months.
What size comes after 12 months?
12 to 18 months. Some brands also sell a single "18 months" size, which lands in the middle of that range. If your baby is long for their age, skip ahead and look at 18 to 24 months.
What size comes after 18 months?
18 to 24 months comes next, for about 26 to 30 lbs and 31 to 34 inches. After that, sizing moves to 2T. If your child is between 18 to 24 months and 2T, pick 24 months for extra diaper room or 2T for a longer, slimmer fit. Shop 18 to 24 month rompers.
What size comes after 24 months?
2T. Toddler sizes replace month sizes at this point: 2T, then 3T, 4T, and 5/6. 24 months and 2T cover a similar weight range, but 2T runs a little longer and slimmer because toddler sizes assume less diaper bulk. Shop bamboo toddler pajamas starting at 2T.
Is 12 to 18 months the same as 18 months?
Close, but not quite. An "18 months" label usually fits the same child as the top half of 12 to 18 months. If your child is right at 18 months and growing fast, 18 to 24 months will last longer.
What size is 2T?
2T is the first toddler size, usually around age 2. In our convertible rompers it fits about 30 to 32 lbs and 33 to 36 inches; in our two-piece pajama sets it fits about 28 to 32 lbs and 33 to 35 inches, since the set is cut a little slimmer. If your 2 year old is tall or already potty training, 2T is the better pick over 24 months. Shop 2T bamboo pajamas.
What size is 3T?
3T fits about 32 to 35 lbs and 35 to 38 inches, usually around age 3. Compared to 2T, it adds roughly 2 to 3 inches in length and a little room through the body. Shop 3T bamboo pajamas.
What size is 4T?
4T fits about 35 to 39 lbs and 38 to 41 inches, usually around age 4. After 4T, most brands move to kid sizes starting at 5/6. Shop 4T bamboo pajamas.
2T vs 3T: what is the difference?
About 3 lbs and 2 to 3 inches of height. In our pajama sets, 2T fits roughly 28 to 32 lbs and 33 to 35 inches; 3T fits 32 to 35 lbs and 35 to 38 inches. If your child is at the top of the 2T range or tall for their age, size up to 3T so the length lasts.
What size does a 3 year old wear?
Most 3 year olds wear 3T. A tall or sturdy 3 year old may fit 4T better, and a petite one may still be in 2T. Check height first, since toddlers usually outgrow length before width. Shop kids bamboo pajamas from 2T to 16.
What size is 110 in baby clothes?
European sizes are the child's height in centimeters. 110 cm is about 43 inches, which lines up with US size 5 (or a roomy 4T). Quick conversions: 62 is about 3 months, 68 is 6 months, 74 is 9 months, 80 is 12 months, 86 is 18 months, 92 is 2T, 98 is 3T, 104 is 4T, 110 is 5.
How to Measure Your Baby Quickly
You do not need a perfect setup, just a quick measurement you can repeat.
- Height: Lay your baby on a flat surface. Measure from the top of the head to the heel, toes relaxed.
- Weight: Use your latest pediatrician weight, or weigh yourself, then weigh yourself holding your baby, and subtract.
- Match to the chart: Compare both numbers to the pajama size chart.
Bam & Stitch Size Snapshot
Our NextHug™ Bamboo runs true to size with a snug fit for safe sleep, and it stretches with your little one. If your child lands between sizes, sizing up gives the comfiest fit and the longest wear.
Convertible Rompers (Newborn to 2T)
| Size | Height | Weight |
|---|---|---|
| Newborn | 18 to 22 in | 8 to 12 lbs |
| 0 to 3 months | 21 to 25 in | 12 to 15 lbs |
| 3 to 6 months | 24 to 27 in | 15 to 18 lbs |
| 6 to 12 months | 26 to 30 in | 18 to 22 lbs |
| 12 to 18 months | 29 to 32 in | 22 to 26 lbs |
| 18 to 24 months | 31 to 34 in | 26 to 30 lbs |
| 2T | 33 to 36 in | 30 to 32 lbs |
Fold-over mittens and footies plus a two-way zipper mean fewer battles at 2 a.m. and a few extra months of wear. Shop all bamboo convertible rompers.
Merry Galaxy Convertible Romper$35.99Shop Now
Main Street Bears Convertible Romper$35.99Shop Now
Sunday Huddle Convertible Romper$35.99Shop Now
Pajama Sets (12 Months to 16)
| Size | Weight | Height |
|---|---|---|
| 12 to 18 months | 22 to 26 lbs | 29 to 31 in |
| 18 to 24 months | 26 to 30 lbs | 31 to 33 in |
| 2T | 28 to 32 lbs | 33 to 35 in |
| 3T | 32 to 35 lbs | 35 to 38 in |
| 4T | 35 to 39 lbs | 38 to 41 in |
| 5/6 | 39 to 48 lbs | 42 to 48 in |
| 7/8 | 48 to 69 lbs | 48 to 54 in |
| 9/10 | 69 to 87 lbs | 54 to 57 in |
| 12/14 | 87 to 110 lbs | 58 to 61 in |
| 16 | 110 to 120 lbs | 61 to 63 in |
Shop bamboo toddler pajamas or all kids pajama sets.
2T vs. 24 Months: What's the Difference?
24 months is still baby sizing, so it's a little more forgiving in the diaper area. 2T is toddler sizing, so it runs a bit longer and slimmer. Still in diapers, especially cloth? 24 months will feel roomier. Tall, or already potty training? 2T usually fits better.
Why Baby Clothing Sizes Vary Between Brands
Two pieces labeled 6 to 9 months from two brands can fit completely differently. European brands often run petite and slim, American brands tend to run true to size but may shrink, and boutique brands vary with fabric and cut. Stretchy fabrics like our NextHug™ Bamboo give you more wiggle room, and following our care instructions (cold wash, low dry) keeps the fit consistent wash after wash.
Tips to Get More Wear Out of Every Size
- When in doubt, size up. A little extra room means longer wear.
- Pick adjustable details. Fold-over cuffs on our convertible rompers buy you extra months.
- Measure every few months. Babies grow fastest in the first year, so check height and weight at each checkup.
- Wash gently. Cold water and low heat keep bamboo soft and true to size, ready for hand-me-downs.
- Keep the next size ready. Have one or two pieces in the next size so a growth spurt never catches you off guard.
FAQ
What if my baby is tall and skinny?
Choose by height first so the length works. If the middle feels a little roomier, that's usually a win for comfort and movement. Tall kids often outgrow length before width.
What size should I buy if we are in between sizes?
Size up. You'll get more wear time, and the fit stays comfortable as your child grows. With cloth diapers, sizing up is strongly recommended for extra room in the seat.
Do Bam & Stitch pajamas run small?
No, they run true to size with a snug fit, which is what's recommended for sleepwear. The bamboo stretches, so they move with your child rather than feeling tight.
Do bamboo pajamas shrink?
They can shrink if washed or dried on high heat. Wash cold and dry low, following our care instructions. If you're torn between two sizes and worried about shrinking, size up.
How do I measure my baby quickly?
Measure height on a flat surface from head to heel. Use your latest weight, or weigh yourself with and without your baby and subtract. Then compare both numbers to our pajama size chart.
Still not sure which size?
Send us your little one's height and weight and we'll help you pick. Ask us here.
Wrapping Up
Sizing doesn't have to be a headache. Measure, check the chart, and size up when you're unsure. Then pick something soft that grows with them, like our bamboo baby clothes, and get back to the snuggles.
Happy shopping!
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