Clinical body calculators
Measures you may meet on a hospital worksheet or a child's growth chart, explained plainly and computed exactly as the published references define them, never as a substitute for the clinician using them.
4 calculators
Child and Teen BMI Percentile Calculator
Work out a child or teenager's BMI percentile on the CDC growth reference, for ages 2 to 20. Adult BMI categories do not apply to a growing body.
Child Growth Percentile Calculator
Height and weight percentiles and z-scores on the CDC growth charts for ages 2 to 20, plus a mid-parental target adult height with its honest error band.
Pregnancy weight gain calculator
The 2009 Institute of Medicine weight gain ranges for pregnancy, set by pre-pregnancy BMI, with the weekly rate and the range expected at the week you are now.
Body Surface Area Calculator
Body surface area from height and weight in all six published formulas (Mosteller, Du Bois, Haycock, Gehan, Fujimoto, Takahira) with the clinical context.
Guides that explain these numbers
Every formula on these pages is written out with its primary source on the methodology page. Results are informational. See the medical disclaimer.