Size chart
Wonder Nation baby size chart
Wonder Nation publishes 11 baby and toddler sizes, Preemie to 4T, by weight and height. Checked against walmart.com on October 4, 2026.
Size chart
- Preemieup to 5 lb
- Newborn5.5 to 7.5 lb
- 0-3M6.5 to 12 lb
- 3-6M12.5 to 16 lb
- 6-9M16.5 to 19 lb
- 12M19.5 to 22 lb
- 18M22.5 to 26 lb
- 24M26.5 to 30 lb
- 2T26.5 to 30 lb
- 3T30.5 to 34 lb
- 4T34.5 to 38 lb
Weight in lb, exactly as Wonder Nation publishes it.
Does Wonder Nation run small or large?
Runs smallAcross 10 size labels that other brands also use, Wonder Nation's published ranges cover smaller babies than the typical chart for the same label, by about a quarter to half a size. Consider the next size up when in doubt.
Based on published size charts compared with other brands. This is not a fit review.
What a typical baby wears in Wonder Nation
For a baby in the middle of the WHO growth chart, with room to grow. Your baby's own measurements give a closer answer in the calculator below.
| Age | Typical weight | Typical length | Wonder Nation size |
|---|---|---|---|
| Birth | 7.3 lb | 19.5 in | 0-3M |
| 3 months | 13.5 lb | 23.9 in | 3-6M |
| 6 months | 16.8 lb | 26.2 in | 6-9M |
| 9 months | 18.9 lb | 28 in | 12M |
| 12 months | 20.5 lb | 29.5 in | 18M |
| 18 months | 23.3 lb | 32.1 in | 2T |
| 2 years | 26.1 lb | 34 in | 3T |
| 3 years | 31.1 lb | 37.6 in | 4T |
The chart as published
The original wording from Wonder Nation's chart, size by size.
| Size | Weight | Height or length | Age |
|---|---|---|---|
| Preemie | Up to 5 | Up to 17 | Not published |
| Newborn | 5½ - 7½ | 17½ - 21 | Not published |
| 0 - 3M | 6½ - 12 | 20½ - 23 | Not published |
| 3 - 6M | 12½ - 16 | 23½ - 26 | Not published |
| 6 - 9M | 16½ - 19 | 26½ - 27½ | Not published |
| 12 Month | 19½ - 22 | 28 - 29½ | Not published |
| 18 Month | 22½ - 26 | 30 - 31½ | Not published |
| 24 Month | 26½ - 30 | 32 - 33½ | Not published |
| 2T | 26½ - 30 | 32 - 33½ | Not published |
| 3T | 30½ - 34 | 34 - 37½ | Not published |
| 4T | 34½ - 38 | 38 - 41½ | Not published |
Notes on this chart. From the Walmart infant and toddler size chart for Wonder Nation. The height column has no unit printed; it is read as inches. 24 Month and 2T are published with identical values. Ranges have half-unit gaps between sizes as published.
Sources
- Brand's own site: https://www.walmart.com/ip/WN-DRESSES-BLUE/17770722849
- Brand's own site: https://i5.walmartimages.com/dfw/4ff9c6c9-f3b0/k2-_2dd6d07c-2947-4450-b901-bc17bc5424b5.v1.js
Retrieved October 4, 2026. Brands update their charts, so check the brand's page before a big purchase. This site is not affiliated with Wonder Nation.
Calculator
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