Peterson Ideal Body Weight Calculator

About this calculator

The Peterson ideal body weight equation, published in 2016 in The American Journal of Clinical Nutrition, calculates ideal weight directly from height and a chosen target BMI: IBW = target BMI × height(m)². Unlike older formulas from the 1970s and 80s (Devine, Robinson, Hamwi, Miller), which use separate constants for men and women and were derived from limited, non-representative samples, Peterson’s equation is sex-neutral and was built by working backward from a target BMI within the healthy range.

The older formulas remain in wide clinical use for drug dosing because hospitals standardized on them decades ago, but researchers have pointed out they don’t correspond cleanly to any defined BMI category, making Peterson’s approach appealing whenever the goal is genuinely “a healthy BMI for this height” rather than matching a legacy dosing convention — clinicians and researchers who want a modern, BMI-anchored reference point choose a target (commonly 22 for a mid-range healthy BMI) and let the equation solve for the matching weight.

Enter your height and a target BMI, and this calculator applies the Peterson equation to give you the corresponding ideal body weight.