Body mass index curves for females 2 to 20 years with severe obesity

• Class I – BMI ≥95^th percentile, or BMI ≥30 kg/m² (whichever is lower)
• Class II – BMI ≥120% of the 95^th percentile curve, or BMI ≥35 kg/m² (whichever is lower)
• Class III – BMI ≥140% of the 95^th percentile curve, or BMI ≥40 kg/m² (whichever is lower)

The black curves (50 through 97) represent BMI percentiles, based on the standard BMI growth reference from the CDC. The blue curves (120 through 180%) are derived by multiplying the 95^th percentile values by 1.2 through 1.8, respectively.