Between age 4 and puberty, humans usually grow at a steadily decreasing rate. This rate is as low as 2 to 2 ½ inches per year.
Humans experience two growth spurts. The first one occurs in early childhood at around the ages of 2 to 3, during which a child grows at a rate of 4 inches per year on average.
The other growth spurt happens during puberty. Girls grow about 3 to 3 ½ inches per year, and boys grow about 4 inches per year during puberty. After teens hit their peak growth spurt, their growth slows steadily until they reach their full adult height, which occurs about four or five years after their peak growth spurt.