Classic Ideal Weight Formulas

This ideal weight calculator applies the four classical height-based formulas — Devine, Robinson, Miller, and Hamwi. Each assumes a base weight at five feet (about 100–112 lb depending on sex) plus a per-inch coefficient, so the four answers cluster within a few pounds.

Clinical Origins

The Devine formula was developed to estimate gentamicin dosing weights and remains the default in most medical calculators. Robinson and Miller refined the coefficients, and Hamwi provides the simplest rule of thumb — all are still quoted in dosing references today.

Use with Judgment

None of these formulas accounts for frame size or muscle mass, so treat the result as one input among many. Combine with BMI range, body-fat measurement, and your own history rather than treating any single number as a target.