Complete Baby & Toddler Size Chart (0-7 Years)
Kids' clothing sizes are confusing and they're even worse when every brand uses a different system. This is the size chart we wish existed when we started Bundle to Bundle. It covers every size from newborn through age 7, organized by age, weight, and height so you can find the right fit no matter what brand you're shopping.
Baby Clothing Size Chart: Newborn to 24 Months
Baby sizes are typically based on age, but weight and height are much more accurate for finding the right fit. A large 3-month-old might already need 6-month clothes. Use the weight and height columns below as your real guide.
| Size | Age | Weight | Height | Notes |
|---|---|---|---|---|
| Preemie | Premature | Up to 5 lbs | Up to 17" | Smallest available size |
| Newborn (NB) | 0–6 weeks | 5–8 lbs | 17–21" | Many babies skip this size entirely |
| 0–3 Months | 0–3 months | 8–12 lbs | 21–24" | The most-used newborn size |
| 3–6 Months | 3–6 months | 12–16 lbs | 24–26.5" | Growth spurts hit hard here |
| 6–9 Months | 6–9 months | 16–20 lbs | 26.5–28.5" | Not all brands carry this size |
| 9–12 Months | 9–12 months | 20–24 lbs | 28.5–30" | Crawlers need reinforced knees |
| 12–18 Months | 12–18 months | 24–28 lbs | 30–32" | Walking changes fit preferences |
| 18–24 Months | 18–24 months | 28–30 lbs | 32–33.5" | Last "baby" size — has diaper room |
How Many Newborn Clothes Do You Actually Need?
One of the biggest mistakes new parents make is overbuying newborn-size clothes. Most babies are only in newborn size for 2–6 weeks (and some skip it entirely if they're born above 8 lbs). We break down exactly how many onesies, sleepers, and outfits you really need in our guide: How Many Newborn Clothes Do You Actually Need?
What Does 0–3 Month Clothes Weight Mean?
When a label says "0–3 months," the weight range is typically 8–12 pounds. But here's the thing — that's the average. If your baby is 11 lbs at birth, they might start in 3–6 month clothes from day one. Always prioritize your baby's actual weight over the age on the label.
Toddler Clothing Size Chart: 2T to 5T
Once your child moves past 24 months, you enter "T" sizing — which stands for "toddler." The big shift here is that T sizes are cut slimmer without diaper room. For a detailed breakdown of when to make the switch, see our 2T vs 24 Months guide.
| Size | Age | Weight | Height | Notes |
|---|---|---|---|---|
| 2T | 2–3 years | 29–32 lbs | 33.5–35" | First toddler size — no diaper room |
| 3T | 3–4 years | 32–35 lbs | 35–38" | Potty-trained fit standard |
| 4T | 4–5 years | 35–39 lbs | 38–41" | Overlaps with size 4 in some brands |
| 5T | 5–6 years | 39–45 lbs | 41–44" | Last T size — transitions to kids' sizing |
Kids Clothing Size Chart: Sizes 4 to 7
After 5T, most brands drop the "T" and switch to standard numeric sizing. These sizes overlap significantly with the T sizes, which creates confusion. The main differences: regular kids' sizes tend to run slightly wider and longer than their T counterparts.
| Size | Age | Weight | Height | Notes |
|---|---|---|---|---|
| 4 | 3.5–4.5 years | 35–39 lbs | 38.5–41.5" | Nearly identical to 4T |
| 5 | 4.5–5.5 years | 39–45 lbs | 41.5–44.5" | Overlaps with 5T |
| 6 | 5.5–6.5 years | 45–50 lbs | 44.5–47" | School-age standard |
| 7 | 6.5–7.5 years | 50–57 lbs | 47–50" | Top of Bundle to Bundle's range |
European Baby Clothing Sizes (70, 80, 90)
If you've ever seen sizes like "80" or "90" on baby clothes and had no idea what they meant, you're not alone. European sizing is based on height in centimeters, which is actually more logical than the US age-based system — once you know the conversion.
| EU Size | Height (cm) | US Equivalent | Approx. Age |
|---|---|---|---|
| 50 | Up to 50 cm | Newborn | 0–1 month |
| 56 | 51–56 cm | 0–3M | 1–2 months |
| 62 | 57–62 cm | 0–3M | 2–4 months |
| 68 | 63–68 cm | 3–6M | 4–6 months |
| 74 | 69–74 cm | 6–9M | 6–9 months |
| 80 | 75–80 cm | 9–12M | 9–12 months |
| 86 | 81–86 cm | 12–18M | 12–18 months |
| 92 | 87–92 cm | 2T | 2 years |
| 98 | 93–98 cm | 3T | 3 years |
| 104 | 99–104 cm | 4T | 4 years |
| 110 | 105–110 cm | 5 | 5 years |
| 116 | 111–116 cm | 6 | 6 years |
| 122 | 117–122 cm | 7 | 7 years |
This matters because many of the best children's clothing brands — the ones we carry at Bundle to Bundle, like Mini Rodini and Hux Baby — use European sizing. For a deeper dive, see our full guide: European Baby Clothing Sizes Explained (70, 80, 90 = What?)
5 Tips for Getting Kids' Clothing Sizes Right
1. Measure, Don't Guess
Take your child's height and weight measurements at least once a month during the first year (growth spurts are no joke). Compare to the charts above — not to the age on the label.
2. Know That Brands Size Differently
A 12-month onesie from Carter's fits differently than one from Petit Bateau. European brands tend to run slimmer and longer; American brands tend to be wider and shorter. When you're renting through Bundle to Bundle's baby collection, you can try multiple brands without committing to any of them.
3. Size Up, Not Down
When in doubt, go one size up. A slightly roomy outfit is comfortable. A too-tight outfit ends up in the donation pile after one wear.
4. Account for Diapers
If your child is in diapers, keep them in "month" sizing (which includes diaper room) until they're reliably potty-trained. Jumping to T sizes too early means tight, uncomfortable bottoms.
5. Stop Buying Sizes They'll Outgrow in Weeks
Between 0 and 2, most babies go through 7 different sizes. That's 7 complete wardrobe rebuilds. This is why renting kids' clothes is becoming the smart move — swap sizes anytime, keep what fits, return what doesn't. See how much you'd save with our Savings Calculator.
How Bundle to Bundle Solves the Sizing Problem
We built Bundle to Bundle because we were tired of spending hundreds of dollars on clothes our kids wore for a few weeks. Here's what makes our kids clothing rental subscription different:
- Sizes newborn through 7 years — covering every size in the charts above
- Mix sizes in one bundle — getting a 3T top and 2T bottom? No problem
- Unlimited rotations — outgrew it? Swap for the next size up, free
- Free shipping both ways — no hidden costs when you exchange
- Premium brands — Mini Rodini, Hux Baby, and more
