Slight gains after acceleration period.
After three years, height varies during day, being greatest on rising, shortest at night.
Weight—Boys[53]
| Age | Range Pounds | Gain Pounds | |
| Birth | 6½-7½ | Weight doubled: 5 months | |
| 3 mo | 12½- | Weight trebled: 1 year | |
| 6 mo | 16-17½ | Weight quadrupled: 2½ years | |
| 9 mo | 17½-20 | Weight fivefold: 4 years | |
| 1 yr | 20½-22 | 12-15 | Loss of weight first 3 days |
| 2 yr | 26½-27½ | 5½-6 | Regained by 7th to 10th day |
| 3 yr | 31½-33½ | 4½-6 | Weekly gain: |
| 4 yr | 35-38 | 3½-4½ | 1st 5 months, 6 to 8 ounces |
| 5 yr | 41-43 | 5-6 | To 1 year, 4 to 6 ounces |
Acceleration period: girls, 11 to 16 years; boys, 13 to 18.
Weight varies during day, being greatest after supper, lowest before breakfast.
Girls nearly cease growing at about 17 years, boys at about 23 years.
Lung capacity is greater in boys than girls, all ages.
Relative Weight and Height Table—Boys [54]
The figures represent weight in pounds