Humans generally stop growing in height when the growth plates in their bones fuse after puberty. For girls, this typically happens about 2 to 2.5 years after their first menstrual period, usually around age 14 or 15. Girls tend to finish their height growth earlier than boys due to earlier puberty timing.
For boys, growth usually stops around age 18 when their growth plates close, but some may continue to have minor growth spurts into their early 20s, with growth generally ending by age 21. This is when the epiphyseal (growth) plates in their long bones fuse, marking the end of height increase.
Overall, most people stop growing taller by their late teens or early twenties, as influenced by genetics, hormones, and overall health during development.
