Ideal Weight Calculator — Multiple Formula Comparison
Find your ideal body weight using four evidence-based formulas: Devine, Robinson, Miller, and Hamwi. Compare results and understand the healthy range.
Ideal Body Weight: Multiple Formulas Explained
Unlike BMI which uses a range, Ideal Body Weight (IBW) formulas calculate a single target weight for a given height. These formulas were originally developed for clinical settings — primarily for calculating medication dosages and ventilator settings — not as strict weight-loss targets. They're best understood as reference points within a broader healthy weight range.
| Formula | Origin | Used For |
|---|---|---|
| Devine | 1974 (pharmacology) | Most common in clinical/drug dosing |
| Robinson | 1983 | Slightly heavier reference weights |
| Miller | 1983 | Slightly lighter reference weights |
| Hamwi | 1964 (endocrinology) | Nutritional assessment |
Hamwi: Men = 48 + 2.7 × (inches over 5 ft); Women = 45.4 + 2.3 × (inches over 5 ft)
Why There's No Single "Ideal" Weight
These formulas often produce estimates that differ by 5–15 lbs for the same height. This variation reflects the reality that there is no single ideal weight — optimal weight is an individual range that depends on your frame size, bone density, muscle mass, age, sex, and health markers. Someone with a large frame and high muscle mass may look and feel best at the upper end of any formula's estimate.
A Practical Goal Framework
Rather than targeting a specific number, aim for a BMI in the healthy range (18.5–24.9) and track functional health metrics: energy levels, strength, blood pressure, blood glucose, and how your clothes fit. Body weight is just one imperfect proxy for health.