Your child's size and growth

Lots of parents wonder whether their child is bigger or smaller than other kids the same age.

To give you a benchmark, here are the values from the 25th percentile to the 75th percentile for weight and height – meaning that half of kids fall within these ranges. A quarter of kids fall above these numbers and a quarter of kids below them.

At each well-child visit, the doctor will weigh and measure your child and tell you his height and weight percentiles. (You can also compute them yourself, using our Growth Percentile Calculator.) Talk with the doctor if you have any concerns about your child's growth.

Baby

 
Birth
 
Boys
Girls
Weight
6.7 - 8.1 pounds
6.5 - 7.8 pounds
Length
19.1 - 20.1 inches
18.9 - 19.8 inches
 
3 months
 
Boys
Girls
Weight
13.0 - 15.2 pounds
11.8 - 14.0 pounds
Length
23.6 - 24.7 inches
23.0 - 24.1 inches
  

Quick tip: For babies born prematurely, use gestational age (not age since birth) when you look up their numbers in this chart.

 
6 months
 
Boys
Girls
Weight
16.2 - 18.8 pounds
14.8 - 17.5 pounds
Length
26.1 - 27.2 inches
25.3 - 26.5 inches
  

Fast fact: By age 6 months, most babies have doubled their birth weight.

 
9 months
 
Boys
Girls
Weight
18.2 - 21.1 pounds
16.7 - 19.7 pounds
Length
27.7 - 28.9 inches
27.0 - 28.3 inches

Toddler

 
 
12 months
 
Boys
Girls
Weight
19.8 - 22.9 pounds
18.2 - 21.4 pounds
Height
29.2 - 30.5 inches
28.5 - 29.8 inches
 
15 months
 
Boys
Girls
Weight
21.1  - 24.5 pounds
19.5 - 23.0 pounds
Height
30.5 - 31.8 inches
29.9 - 31.2 inches
 
18 months
 
Boys
Girls
Weight
22.4 - 26.0 pounds
20.8 - 24.5 pounds
Height
31.7 - 33.1 inches
31.0 - 32.5 inches
 
21 months
 
Boys
Girls
Weight
23.6 - 27.5 pounds
22.0 - 26.0 pounds
Height
32.7 - 34.3 inches
32.1 - 33.8 inches

Preschooler

 
 
24 months
 
Boys
Girls
Weight
24.8 - 28.9 pounds
23.3 - 27.5 pounds
Height
33.8 - 35.4 inches
33.2 - 34.9 inches
 
27 months
 
Boys
Girls
Weight
27.0 - 31.2 pounds
25.8 - 30.0 pounds
Height
34.1 - 36.1 inches
33.7 - 35.6 inches
 
30 months
 
Boys
Girls
Weight
27.8 - 32.2 pounds
26.7 - 31.1 pounds
Height
35.0 - 37.0 inches
34.6 - 36.6 inches
 
33 months
 
Boys
Girls
Weight
28.6 - 33.2 pounds
27.6 - 32.3 pounds
Height
35.8 - 37.8 inches
35.4 - 37.4 inches
 
36 months
 
Boys
Girls
Weight
29.5 - 34.3 pounds
28.4 - 33.4 pounds
Height
36.5 - 38.6 inches
36.0 - 38.1 inches
 
4 years
 
Boys
Girls
Weight
33.3 - 39.1 pounds
32.2 - 38.5 pounds
Height
39.2 - 41.5 inches
38.6 - 41.0 inches

Big Kid

 
 
5 years
 
Boys
Girls
Weight
37.5 - 44.7 pounds
36.3 - 44.0 pounds
Height
41.7 - 44.2 inches
41.3 - 43.8 inches
 
6 years
 
Boys
Girls
Weight
41.9 - 50.6 pounds
40.8 - 50.0 pounds
Height
44.2 - 46.9 inches
43.9 - 46.7 inches
 
7 years
 
Boys
Girls
Weight
46.5 - 56.8 pounds
45.6 - 56.6 pounds
Height
46.6 - 49.5 inches
46.5 - 49.4 inches
 
8 years
 
Boys
Girls
Weight
51.5 - 63.6 pounds
50.9 - 64.3 pounds
Height
48.9 - 52.0 inches
48.8 - 51.9 inches