‹ Average height by age

Average height for a 6-year-old boy

At exactly 6 years old, the median boy in the US is 3'9½" (115.4 cm) tall, according to the CDC growth charts. Half of 6-year-old boys are between 3'8" and 3'11", and about 9 in 10 fall between 3'6" and 4'0½".

Height percentiles for 6-year-old boys

CDC 2000 stature-for-age chart, at 6 years 0 months.

PercentileHeightcmin
3rd3'5½"105.941.7
5th3'6"107.142.2
10th3'7"108.942.9
25th3'8"112.044.1
50th (median)3'9½"115.445.4
75th3'11"118.846.8
90th4'0"121.848.0
95th4'0½"123.648.7
97th4'1"124.849.1

What’s typical at 6 for boys

Between 6 and 7, the median boy grows about 2½ in (6.4 cm) — from 3'9½" to 4'0".

A median 6-year-old boy has reached about 65% of the CDC's median adult height for men (5'9½"), so roughly 24 in (61.5 cm) of growth is still typical from here.

This is the steady stretch of childhood: growth runs at a fairly even pace and most boys track along the same percentile line year after year. Puberty, and the growth spurt that comes with it, is still years away — boys typically start between 9 and 14.

How to read a percentile

A percentile compares a child with others of the same age and sex on the CDC 2000 growth charts — the same L, M and S values a pediatrician’s chart is drawn from, and where every number on this page comes from. The 50th percentile is the median: half of boys that age are shorter and half are taller. The 5th and 95th bracket the middle 90%.

Pediatricians care less about the number than the line. A child who stays near the same percentile year after year is growing normally, whatever that percentile is — a steady 15th is healthier than a 60th that has just dropped from the 90th. Crossing two of the major lines, or sitting below the 3rd, is the usual cue to have a pediatrician take a look. None of this is medical advice.

How tall will a 6-year-old boy be as an adult?

Height at 6 is one input. The calculator combines it with both parents’ heights and puberty timing to give the range adult height will most likely land in — free, no account.

Try the height calculator

The MaxHeight app shows the number inside that range and sharpens it as you log — free to download on the App Store.

Source: CDC 2000 growth charts, stature-for-age LMS parameters (statage.csv). Adult figures: NHANES 2015–2018. MaxHeight is not affiliated with or endorsed by the CDC.