Height Gains from Birth to Age 18

The range of height (on this page) and weight (see page A-11) are for children in the United States. The columns labeled “50th” (the fiftieth percentile) show the average; the columns labeled “90th” (the ninetieth percentile) show the size of children taller and heavier than 90 percent of their contemporaries; and the columns labeled “10th” (the tenth percentile) show the size of children who are taller than only 10 percent of their peers. Note that girls are slightly shorter, on average, than boys.

Same Data, Different Form

The columns of numbers in the table to the right provide detailed and precise information about height ranges for every year of childhood. The illustration above shows the same information in graphic form for ages 2–6. The same is done for weight ranges on page A-11. Ages 2–6 are singled out because that is the period during which a child’s eating habits are set. Which form of data presentation do you think is easier to understand?

Boys: percentiles Girls: percentiles
AGE 10th 50th 90th 10th 50th 90th
Birth 47.5 50.5 53.5 46.5 49.9 52.0
(18¾) (20) (21) (18¼) (19¾) (20½)
1 51.3 54.6 57.7 50.2 53.5 56.1
month (20¼) (21½) (22¾) (19¾) (21) (22)
3 57.7 61.1 64.5 56.2 59.5 62.7
months (22¾) (24) (25½) (22¼) (23½) (24¾)
6 64.4 67.8 71.3 62.6 65.9 69.4
months (25¼) (26¾) (28) (24¾) (26) (27¼)
9 69.1 72.3 75.9 67.0 70.4 74.0
months (27¼) (28½) (30) (26½) (27¾) (29¼)
12 72.8 76.1 79.8 70.8 74.3 78.0
months (28¾) (30) (31½) (27¾) (29¼) (30¾)
18 78.7 82.4 86.6 77.2 80.9 85.0
months (31) (32½) (34) (30½) (31¾) (33½)
24 83.5 87.6 92.2 82.5 86.5 90.8
months (32¾) (34½) (36¼) (32½) (34) (35¾)
3 90.3 94.9 100.1 89.3 94.1 99.0
years (35½) (37¼) (39½) (35¼) (37) (39)
4 97.3 102.9 108.2 96.4 101.6 106.6
years (38¼) (40½) (42½) (38) (40) (42)
5 103.7 109.9 115.4 102.7 108.4 113.8
years (40¾) (43¼) (45½) (40½) (42¾) (44¾)
6 109.6 116.1 121.9 108.4 114.6 120.8
years (43½) (45¾) (48) (42¾) (45) (47½)
7 115.0 121.7 127.9 113.6 120.6 127.6
years (45¼) (48) (50¼) (44¾) (47½) (50¼)
8 120.2 127.0 133.6 118.7 126.4 134.2
years (47¼) (50) (52½) (46¾) (49¾) (52¾)
9 125.2 132.2 139.4 123.9 132.2 140.7
years (49½) (52) (55) (48¾) (52) (55½)
10 130.1 137.5 145.5 129.5 138.3 147.2
years (51¼) (54¼) (57¼) (51) (54½) (58)
11 135.1 143.33 152.1 135.6 144.8 153.7
years (53¼) (56½) (60) (53½) (57) (60½)
12 140.3 149.7 159.4 142.3 151.5 160.0
years (55¼) (59) (62¾) (56) (59¾) (63)
13 145.8 156.5 167.0 148.0 157.1 165.3
years (57½) (61½) (65¾) (58¼) (61¾) (65)
14 151.8 63.1 173.8 151.5 160.4 168.7
years (59¾) (64¼) (68½) (59¾) (63¼) (66½)
15 158.2 169.0 178.9 153.2 161.8 170.5
years (62¼) (66½) (70½) (60¼) (63¾) (67¼)
16 163.9 173.5 182.4 154.1 162.4 171.1
years (64½) (68¼) (71¾) (60¾) (64) (67¼)
17 167.7 176.2 184.4 155.1 163.1 171.2
years (66) (69¼) (72½) (61) (64¼) (67½)
18 168.7 176.8 185.3 156.0 163.7 171.0
years (66½) (69½) (73) (61½) (64½) (67¼)
Source: These data are those of the National Center for Health Statistics (NCHS), Health Resources Administration, DHHS. They were based on studies of The Fels Research Institute, Yellow Springs, Ohio. These data were first made available with the help of William M. Moore, M.D., of Ross Laboratories, who supplied the conversion from metric measurements to approximate inches and pounds. This help is gratefully acknowledged.
Table : Length in Centimeters (and Inches)

A-11