BMI for girls at 2 years

At 2 years, the median BMI for girls on the CDC 2000 growth charts is 16.4 kg/m²: half of girls this age have a lower BMI and half a higher one. The middle half of girls, from the 25th to the 75th percentile, falls between 15.5 and 17.4 kg/m², a spread of 1.9 kg/m². The outer lines of CDC’s BMI-for-age chart, the 5th and 95th percentiles, sit at 14.4 and 19.1 kg/m².

By 3 years it reaches 15.7 kg/m².

For boys at 2 years the median is 16.6 kg/m², 0.2 kg/m² more than for girls, which is why the charts are drawn separately by sex.

CDC uses BMI-for-age, not weight-for-length, from age 2. At 2 years the 85th percentile for girls is 18.0 and the 95th is 19.1 kg/m². Above the 95th percentile, CDC's 2022 extended charts replace the original curve, so the 99th percentile here is 21.1 kg/m², computed with the extended method.

Reading the table: a girl at 2 years with a BMI of 17.0 kg/m² is at about the 65th percentile, meaning that out of 100 girls this age, about 65 have a lower BMI.