Brand vs brand

Cat & Jack vs Wonder Nation sizes

Of Cat & Jack's 11 baby and toddler sizes, 3 line up closely with a Wonder Nation size, 8 are partial matches, and 0 have no clean match. Both charts list weight and height, so the comparison uses both.

Closest pairs: Cat & Jack 0-3M = Wonder Nation 0-3M, Cat & Jack 3-6M = Wonder Nation 3-6M, Cat & Jack 6-9M = Wonder Nation 6-9M.

Watch the labels: Cat & Jack 0-3M is closer to Wonder Nation 0-3M than to Wonder Nation's own 0-3M; Cat & Jack 3-6M is closer to Wonder Nation 3-6M than to Wonder Nation's own 3-6M; Cat & Jack 6-9M is closer to Wonder Nation 6-9M than to Wonder Nation's own 6-9M.

Cat & Jack True to sizeWonder Nation Runs small

Based on published size charts compared with other brands.

Size by size, on one scale

Each block is one size, placed where the brand's chart puts it. Blocks that sit above each other fit the same baby.

Weight (lb)

Cat & Jack

Preemie: up to 5.5 lb
Newborn: 6 to 8 lb
0-3M: 9 to 12 lb
3-6M: 12.5 to 16 lb
6-9M: 16.5 to 19.5 lb
12M: 20 to 23 lb
18M: 23.5 to 26 lb
24M: 26.5 to 28 lb
2T: 26.5 to 28 lb
3T: 28.5 to 32 lb
4T: 32.5 to 37 lb

Wonder Nation

Preemie: up to 5 lb
Newborn: 5.5 to 7.5 lb
0-3M: 6.5 to 12 lb
3-6M: 12.5 to 16 lb
6-9M: 16.5 to 19 lb
12M: 19.5 to 22 lb
18M: 22.5 to 26 lb
24M: 26.5 to 30 lb
2T: 26.5 to 30 lb
3T: 30.5 to 34 lb
4T: 34.5 to 38 lb

Height (in)

Cat & Jack

Preemie: up to 17.5 in
Newborn: 18 to 20 in
0-3M: 20.5 to 23.5 in
3-6M: 24 to 25.5 in
6-9M: 26 to 27.5 in
12M: 28 to 30.5 in
18M: 31 to 32.5 in
24M: 33 to 35.5 in
2T: 33 to 35.5 in
3T: 36 to 38.5 in
4T: 39 to 43 in

Wonder Nation

Preemie: up to 17 in
Newborn: 17.5 to 21 in
0-3M: 20.5 to 23 in
3-6M: 23.5 to 26 in
6-9M: 26.5 to 27.5 in
12M: 28 to 29.5 in
18M: 30 to 31.5 in
24M: 32 to 33.5 in
2T: 32 to 33.5 in
3T: 34 to 37.5 in
4T: 38 to 41.5 in

Cat & Jack size to Wonder Nation size

Cat & Jack	Closest Wonder Nation	Match	Weight: Cat & Jack / Wonder Nation	Height: Cat & Jack / Wonder Nation
Preemie	Preemie	Partial	up to 5.5 lb / up to 5 lb	up to 17.5 in / up to 17 in
Newborn	Newborn	Partial	6 to 8 lb / 5.5 to 7.5 lb	18 to 20 in / 17.5 to 21 in
0-3M	0-3M	Close match	9 to 12 lb / 6.5 to 12 lb	20.5 to 23.5 in / 20.5 to 23 in
3-6M	3-6M	Close match	12.5 to 16 lb / 12.5 to 16 lb	24 to 25.5 in / 23.5 to 26 in
6-9M	6-9M	Close match	16.5 to 19.5 lb / 16.5 to 19 lb	26 to 27.5 in / 26.5 to 27.5 in
12M	12M	Partial	20 to 23 lb / 19.5 to 22 lb	28 to 30.5 in / 28 to 29.5 in
18M	18M	Partial	23.5 to 26 lb / 22.5 to 26 lb	31 to 32.5 in / 30 to 31.5 in
24M	24M	Partial	26.5 to 28 lb / 26.5 to 30 lb	33 to 35.5 in / 32 to 33.5 in
2T	24M	Partial	26.5 to 28 lb / 26.5 to 30 lb	33 to 35.5 in / 32 to 33.5 in
3T	3T	Partial	28.5 to 32 lb / 30.5 to 34 lb	36 to 38.5 in / 34 to 37.5 in
4T	4T	Partial	32.5 to 37 lb / 34.5 to 38 lb	39 to 43 in / 38 to 41.5 in

Wonder Nation size to Cat & Jack size

Wonder Nation	Closest Cat & Jack	Match	Weight: Wonder Nation / Cat & Jack	Height: Wonder Nation / Cat & Jack
Preemie	Preemie	Partial	up to 5 lb / up to 5.5 lb	up to 17 in / up to 17.5 in
Newborn	Newborn	Partial	5.5 to 7.5 lb / 6 to 8 lb	17.5 to 21 in / 18 to 20 in
0-3M	0-3M	Close match	6.5 to 12 lb / 9 to 12 lb	20.5 to 23 in / 20.5 to 23.5 in
3-6M	3-6M	Close match	12.5 to 16 lb / 12.5 to 16 lb	23.5 to 26 in / 24 to 25.5 in
6-9M	6-9M	Close match	16.5 to 19 lb / 16.5 to 19.5 lb	26.5 to 27.5 in / 26 to 27.5 in
12M	12M	Partial	19.5 to 22 lb / 20 to 23 lb	28 to 29.5 in / 28 to 30.5 in
18M	18M	Partial	22.5 to 26 lb / 23.5 to 26 lb	30 to 31.5 in / 31 to 32.5 in
24M	24M	Partial	26.5 to 30 lb / 26.5 to 28 lb	32 to 33.5 in / 33 to 35.5 in
2T	24M	Partial	26.5 to 30 lb / 26.5 to 28 lb	32 to 33.5 in / 33 to 35.5 in
3T	3T	Partial	30.5 to 34 lb / 28.5 to 32 lb	34 to 37.5 in / 36 to 38.5 in
4T	4T	Partial	34.5 to 38 lb / 32.5 to 37 lb	38 to 41.5 in / 39 to 43 in

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Every Cat & Jack size in Wonder Nation

Close match

Cat & Jack 0-3M lines up closely with Wonder Nation 0-3M.

Weight (lb)

Cat & Jack 0-3M 9 to 12 lb

Wonder Nation Newborn 5.5 to 7.5 lb

Wonder Nation 0-3M 6.5 to 12 lb

Height (in)

Cat & Jack 0-3M 20.5 to 23.5 in

Wonder Nation Newborn 17.5 to 21 in

Wonder Nation 0-3M 20.5 to 23 in

The shaded column is the Cat & Jack range. Bars show what each brand publishes for the size.

Based on published size charts. Cat & Jack chart and Wonder Nation chart.

More comparisons

Charts retrieved October 4, 2026 (Cat & Jack) and October 4, 2026 (Wonder Nation). Sources are listed on each brand page. This site is not affiliated with either brand.