Baby Clothing Size Calculator
Enter your baby's age in months to see the clothing size that usually fits. Add weight or height for a better match. Sizes are a starting point, not a promise — every brand cuts a little differently.
Suggested size
3-6M
Between two sizes? Go with the larger one.
Age to size guide
| Size | Age | Weight | Height |
|---|---|---|---|
| Newborn | 0-1 mo | 2.5–4.3 kg | 46–56 cm |
| 0-3M | 0-3 mo | 3.6–5.7 kg | 55–61 cm |
| 3-6M | 3-6 mo | 5.7–7.5 kg | 61–67 cm |
| 6-9M | 6-9 mo | 7.5–9 kg | 67–72 cm |
| 9-12M | 9-12 mo | 9–10.4 kg | 72–78 cm |
| 12-18M | 12-18 mo | 10.4–11.8 kg | 78–83 cm |
| 18-24M / 2T | 18-24 mo | 11.8–13.5 kg | 83–92 cm |
Typical ranges only. Weight and height vary by brand — check the label's own chart.
General information, not medical advice.
How it works
Type your baby's age in months. We map it to the common labels you'll see on tags: Newborn, 0-3M, 3-6M, 6-9M, 9-12M, 12-18M, and 18-24M (often shown as 2T).
If you know your baby's weight or height, add them too. If the measurement points to a bigger size than age alone, we suggest sizing up so the clothes aren't too snug.
When your baby is between two sizes, pick the larger one. Babies grow fast, and a little room is better than a tight fit that's outgrown in a week.
Frequently asked questions
Why do clothing sizes vary so much between brands? +
There's no single standard for baby clothes. Each brand sets its own measurements, so a 6-9M from one label can fit differently than another. Always check the brand's own weight and height chart when you can.
Should I buy the size for my baby's exact age? +
Not always. Babies of the same age can differ a lot in size. If your baby is heavier, taller, or growing fast, size up. Many parents buy one size ahead so the clothes last longer.
What does 2T mean? +
2T stands for 'toddler 2' and roughly covers 18-24 months and up. Toddler sizes are cut for a more upright, on-the-move child, often with room for a diaper, compared with baby sizes.
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