Ideal Body Weight Calculator
4 formulas side-by-side for a complete picture
What Is "Ideal Body Weight" — And Does It Actually Mean Anything?
Ideal body weight (IBW) formulas were developed in the 1960s–1980s primarily for clinical drug dosing — not for body composition goals. The Devine formula (1974) was created specifically to calculate medication doses, not to define aesthetic or health targets. The Robinson and Miller formulas followed in 1983 with slightly different coefficients but the same basic structure: a base weight for 5 feet of height, plus an increment per additional inch.
The critical problem with all IBW formulas is that they use only height and sex, completely ignoring body composition (muscle vs. fat), age-related changes, bone density, or individual genetic variation. A bodybuilder and a sedentary person of the same height get the same IBW calculation — a clinically meaningless result for any practical purpose.
A Better Way to Think About Target Weight
Rather than targeting a specific IBW number, consider: What is the weight at which your body fat percentage falls in the healthy/athletic range for your sex and age? This can be calculated from your current weight and body fat % using the Navy method or DEXA scan. For most people, this produces a target that's more meaningful than any IBW formula.