Size chart
Janie and Jack baby size chart
Janie and Jack publishes 10 baby and toddler sizes, Preemie to 4, by weight and height. Checked against janieandjack.com on October 4, 2026.
Size chart
- Preemieup to 5 lb
- Newborn5 to 8 lb
- 0-3M8 to 12 lb
- 3-6M12 to 17 lb
- 6-12M17 to 22 lb
- 12-18M22 to 27 lb
- 18-24M27 to 30 lb
- 2T30 to 33 lb
- 333 to 36 lb
- 436 to 40 lb
Weight in lb, exactly as Janie and Jack publishes it.
Does Janie and Jack run small or large?
True to sizeAcross 9 size labels that other brands also use, Janie and Jack's published ranges sit close to the middle of the pack. The same label covers about the same baby.
Based on published size charts compared with other brands. This is not a fit review.
What a typical baby wears in Janie and Jack
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 | Janie and Jack 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 | 6-12M |
| 9 months | 18.9 lb | 28 in | 6-12M |
| 12 months | 20.5 lb | 29.5 in | 12-18M |
| 18 months | 23.3 lb | 32.1 in | 18-24M |
| 2 years | 26.1 lb | 34 in | 2T |
| 3 years | 31.1 lb | 37.6 in | 3 |
The chart as published
The original wording from Janie and Jack's chart, size by size.
| Size | Weight | Height or length | Age |
|---|---|---|---|
| Preemie/Up to 5 lbs | Up to 5 lbs | Up to 17 in | Not published |
| Newborn | 5 - 8 lbs | 17 - 18 in | Not published |
| 0 - 3 m | 8 - 12 lbs | 19 - 23 in | Not published |
| 3 - 6 m | 12 - 17 lbs | 23 - 25 in | Not published |
| 6 - 12 m | 17 - 22 lbs | 25 - 29 in | Not published |
| 12 - 18 m | 22 - 27 lbs | 29 - 31 in | Not published |
| 18 - 24 m | 27 - 30 lbs | 31 - 33 in | Not published |
| 2T | 30 - 33 lbs | 33 - 36 in | Not published |
| 3 | 33 - 36 lbs | 36 - 39 in | Not published |
| 4 | 36 - 40 lbs | 39 - 42 in | Not published |
Notes on this chart. Preemie through 18 - 24 m come from the brand's baby chart; 2T, 3, and 4 come from the girl and boy charts, which match. The brand labels sizes above 2T as 3 and 4. There is a published gap: Newborn height ends at 18 in and 0 - 3 m starts at 19 in.
Sources
- Brand's own site: https://www.janieandjack.com/janieandjack-size-charts.html
Retrieved October 4, 2026. Brands update their charts, so check the brand's page before a big purchase. This site is not affiliated with Janie and Jack.
Calculator
What Janie and Jack size on your date?
Start with a birth or due date
Sizes for each brand you pick will appear here, ready for the date you choose.