Brand vs brand

Carter's vs Primary sizes

Of Carter's 12 baby and toddler sizes, 1 line up closely with a Primary size, 9 are partial matches, and 2 have no clean match. Both charts list weight and height, so the comparison uses both.

Closest pairs: Carter's 9M = Primary 9-12M.

Watch the labels: Carter's Newborn is closer to Primary Newborn than to Primary's own Newborn; Carter's 2T is closer to Primary 3 than to Primary's own 2T; Carter's 3T is closer to Primary 2 than to Primary's own 3T.

Carter's 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)

Carter's

Up to 5 lb: up to 5 lb
Preemie: up to 6 lb
Newborn: 6 to 9 lb
3M: 9 to 12.5 lb
6M: 12.5 to 17 lb
9M: 17 to 21 lb
12M: 21 to 25 lb
18M: 25 to 28 lb
24M: 28 to 30 lb
2T: 29 to 31 lb
3T: 31 to 33 lb
4T: 33 to 37.5 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)

Carter's

Up to 5 lb: up to 17 in
Preemie: up to 18 in
Newborn: 18 to 21.5 in
3M: 21.5 to 24 in
6M: 24 to 27 in
9M: 27 to 28.5 in
12M: 28.5 to 30 in
18M: 30 to 32 in
24M: 32 to 34 in
2T: 35 to 36.5 in
3T: 36.5 to 39 in
4T: 39 to 41.5 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

Carter's size to Primary size

Carter's	Closest Primary	Match	Weight: Carter's / Primary	Height: Carter's / Primary
Up to 5 lb	Newborn	No clean match	up to 5 lb / 5.1 to 9 lb	up to 17 in / up to 18.1 in
Preemie	Newborn	Partial	up to 6 lb / 5.1 to 9 lb	up to 18 in / up to 18.1 in
Newborn	Newborn	Partial	6 to 9 lb / 5.1 to 9 lb	18 to 21.5 in / up to 18.1 in
3M	0-3M	Partial	9 to 12.5 lb / 9 to 11.9 lb	21.5 to 24 in / 18.1 to 22.8 in
6M	6-9M	Partial	12.5 to 17 lb / 15 to 18.1 lb	24 to 27 in / 25.2 to 27.2 in
9M	9-12M	Close match	17 to 21 lb / 18.1 to 22 lb	27 to 28.5 in / 27.2 to 29.1 in
12M	12-18M	Partial	21 to 25 lb / 22 to 26.9 lb	28.5 to 30 in / 29.1 to 31.1 in
18M	12-18M	Partial	25 to 28 lb / 22 to 26.9 lb	30 to 32 in / 29.1 to 31.1 in
24M	18-24M	Partial	28 to 30 lb / 26.9 to 30 lb	32 to 34 in / 31.1 to 33.1 in
2T	3	No clean match	29 to 31 lb / 33.1 to 35.9 lb	35 to 36.5 in / 35 to 38.2 in
3T	2	Partial	31 to 33 lb / 30 to 33.1 lb	36.5 to 39 in / 33.1 to 35 in
4T	4	Partial	33 to 37.5 lb / 35.9 to 39.9 lb	39 to 41.5 in / 38.2 to 40.9 in

Primary size to Carter's size

Primary	Closest Carter's	Match	Weight: Primary / Carter's	Height: Primary / Carter's
Newborn	Newborn	Partial	5.1 to 9 lb / 6 to 9 lb	up to 18.1 in / 18 to 21.5 in
0-3M	3M	Partial	9 to 11.9 lb / 9 to 12.5 lb	18.1 to 22.8 in / 21.5 to 24 in
3-6M	6M	Partial	11.9 to 15 lb / 12.5 to 17 lb	22.8 to 25.2 in / 24 to 27 in
6-9M	6M	Partial	15 to 18.1 lb / 12.5 to 17 lb	25.2 to 27.2 in / 24 to 27 in
6-12M	9M	Partial	15 to 22 lb / 17 to 21 lb	25.2 to 29.1 in / 27 to 28.5 in
9-12M	9M	Close match	18.1 to 22 lb / 17 to 21 lb	27.2 to 29.1 in / 27 to 28.5 in
12-18M	12M	Partial	22 to 26.9 lb / 21 to 25 lb	29.1 to 31.1 in / 28.5 to 30 in
18-24M	24M	Partial	26.9 to 30 lb / 28 to 30 lb	31.1 to 33.1 in / 32 to 34 in
2	3T	Partial	30 to 33.1 lb / 31 to 33 lb	33.1 to 35 in / 36.5 to 39 in
3	4T	Partial	33.1 to 35.9 lb / 33 to 37.5 lb	35 to 38.2 in / 39 to 41.5 in
4	4T	Partial	35.9 to 39.9 lb / 33 to 37.5 lb	38.2 to 40.9 in / 39 to 41.5 in

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Size

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Every Carter's size in Primary

Close match

Carter's 9M lines up closely with Primary 9-12M.

Weight (lb)

Carter's 9M 17 to 21 lb

Primary 6-9M 15 to 18.1 lb

Primary 6-12M 15 to 22 lb

Primary 9-12M 18.1 to 22 lb

Height (in)

Carter's 9M 27 to 28.5 in

Primary 6-9M 25.2 to 27.2 in

Primary 6-12M 25.2 to 29.1 in

Primary 9-12M 27.2 to 29.1 in

The shaded column is the Carter's range. Bars show what each brand publishes for the size.

Based on published size charts. Carter's chart and Primary chart.

More comparisons

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