Four medically established formulas — Hamwi, Devine, Robinson, and Miller — give you a realistic healthy weight range based on your height, not a single misleading number.
4 medical formulas · Enter your height below
Breakdown by formula
Ideal weight formulas are population-level estimates. They do not account for muscle mass, bone density, or age. Consult a healthcare professional for personalised guidance.
Ideal body weight (IBW) is a target weight range derived from height — and sometimes sex — that is associated with favourable health outcomes in population studies. Clinically, it is used to calculate medication dosages, assess nutritional needs, and set realistic weight goals.
The concept dates back to early twentieth-century insurance actuarial tables, which noted correlations between body weight and mortality. Several researchers subsequently developed more precise mathematical formulas, each using slightly different assumptions about human body proportions.
Each formula was developed for a different clinical purpose using different population data. Presenting all four gives you a realistic range rather than false precision. The spread between the lowest and highest estimate — typically 4–8 kg — reflects genuine scientific uncertainty about what constitutes a single "ideal" weight for any height.
| Formula | Year | Original purpose |
|---|---|---|
| Hamwi | 1964 | Diabetes management guidelines |
| Devine | 1974 | Drug dosage calculations |
| Robinson | 1983 | Refined Devine with updated data |
| Miller | 1983 | Broader actuarial dataset |
The Devine formula is most widely used in medicine for drug dosing. Robinson is considered an improvement for general weight assessment. Miller typically produces the highest estimates of the four.