Brand vs brand

Cat & Jack vs Primary sizes

Of Cat & Jack's 11 baby and toddler sizes, 1 line up closely with a Primary size, 10 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 = Primary 0-3M.

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

Cat & Jack True to sizePrimary True to size

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

Primary

Newborn: 5.1 to 9 lb
0-3M: 9 to 11.9 lb
3-6M: 11.9 to 15 lb
6-9M: 15 to 18.1 lb
6-12M: 15 to 22 lb
9-12M: 18.1 to 22 lb
12-18M: 22 to 26.9 lb
18-24M: 26.9 to 30 lb
2: 30 to 33.1 lb
3: 33.1 to 35.9 lb
4: 35.9 to 39.9 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

Primary

Newborn: up to 18.1 in
0-3M: 18.1 to 22.8 in
3-6M: 22.8 to 25.2 in
6-9M: 25.2 to 27.2 in
6-12M: 25.2 to 29.1 in
9-12M: 27.2 to 29.1 in
12-18M: 29.1 to 31.1 in
18-24M: 31.1 to 33.1 in
2: 33.1 to 35 in
3: 35 to 38.2 in
4: 38.2 to 40.9 in

Cat & Jack size to Primary size

Cat & Jack	Closest Primary	Match	Weight: Cat & Jack / Primary	Height: Cat & Jack / Primary
Preemie	Newborn	Partial	up to 5.5 lb / 5.1 to 9 lb	up to 17.5 in / up to 18.1 in
Newborn	Newborn	Partial	6 to 8 lb / 5.1 to 9 lb	18 to 20 in / up to 18.1 in
0-3M	0-3M	Close match	9 to 12 lb / 9 to 11.9 lb	20.5 to 23.5 in / 18.1 to 22.8 in
3-6M	3-6M	Partial	12.5 to 16 lb / 11.9 to 15 lb	24 to 25.5 in / 22.8 to 25.2 in
6-9M	6-9M	Partial	16.5 to 19.5 lb / 15 to 18.1 lb	26 to 27.5 in / 25.2 to 27.2 in
12M	9-12M	Partial	20 to 23 lb / 18.1 to 22 lb	28 to 30.5 in / 27.2 to 29.1 in
18M	18-24M	Partial	23.5 to 26 lb / 26.9 to 30 lb	31 to 32.5 in / 31.1 to 33.1 in
24M	2	Partial	26.5 to 28 lb / 30 to 33.1 lb	33 to 35.5 in / 33.1 to 35 in
2T	2	Partial	26.5 to 28 lb / 30 to 33.1 lb	33 to 35.5 in / 33.1 to 35 in
3T	3	Partial	28.5 to 32 lb / 33.1 to 35.9 lb	36 to 38.5 in / 35 to 38.2 in
4T	3	Partial	32.5 to 37 lb / 33.1 to 35.9 lb	39 to 43 in / 35 to 38.2 in

Primary size to Cat & Jack size

Primary	Closest Cat & Jack	Match	Weight: Primary / Cat & Jack	Height: Primary / Cat & Jack
Newborn	Preemie	Partial	5.1 to 9 lb / up to 5.5 lb	up to 18.1 in / up to 17.5 in
0-3M	0-3M	Close match	9 to 11.9 lb / 9 to 12 lb	18.1 to 22.8 in / 20.5 to 23.5 in
3-6M	3-6M	Partial	11.9 to 15 lb / 12.5 to 16 lb	22.8 to 25.2 in / 24 to 25.5 in
6-9M	6-9M	Partial	15 to 18.1 lb / 16.5 to 19.5 lb	25.2 to 27.2 in / 26 to 27.5 in
6-12M	6-9M	Partial	15 to 22 lb / 16.5 to 19.5 lb	25.2 to 29.1 in / 26 to 27.5 in
9-12M	12M	Partial	18.1 to 22 lb / 20 to 23 lb	27.2 to 29.1 in / 28 to 30.5 in
12-18M	12M	Partial	22 to 26.9 lb / 20 to 23 lb	29.1 to 31.1 in / 28 to 30.5 in
18-24M	18M	Partial	26.9 to 30 lb / 23.5 to 26 lb	31.1 to 33.1 in / 31 to 32.5 in
2	24M	Partial	30 to 33.1 lb / 26.5 to 28 lb	33.1 to 35 in / 33 to 35.5 in
3	4T	Partial	33.1 to 35.9 lb / 32.5 to 37 lb	35 to 38.2 in / 39 to 43 in
4	4T	Partial	35.9 to 39.9 lb / 32.5 to 37 lb	38.2 to 40.9 in / 39 to 43 in

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Size

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Every Cat & Jack size in Primary

Close match

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

Weight (lb)

Cat & Jack 0-3M 9 to 12 lb

Primary Newborn 5.1 to 9 lb

Primary 0-3M 9 to 11.9 lb

Primary 3-6M 11.9 to 15 lb

Height (in)

Cat & Jack 0-3M 20.5 to 23.5 in

Primary Newborn up to 18.1 in

Primary 0-3M 18.1 to 22.8 in

Primary 3-6M 22.8 to 25.2 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 Primary chart.

More comparisons

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