Ideal Weight Calculator
Calculate ideal body weight using four clinical formulas and see the resulting range for your height, sex, and frame size.
Unit system
Recommended range
65.2–66.7 kg
143.7–147 lb
Four formulas comparison
| Formula | IBW (kg) | IBW (lb) | BMI |
|---|---|---|---|
| Devine (1974) | 65.9 | 145.3 | 22.8 |
| Robinson (1983) | 65.2 | 143.7 | 22.6 |
| Miller (1983) | 66 | 145.5 | 22.8 |
| Hamwi (1964) | 66.7 | 147 | 23.1 |
Frame-adjusted range (Hamwi)
Small frame
60 kg
132.3 lb
Medium frame
66.7 kg
147 lb
Large frame
73.4 kg
161.8 lb
Clinical IBW formulas were developed for medication dosing, not fitness targets. Use as a reference, not a prescription. Individual factors such as muscle mass, bone density, and body composition are not captured by these formulas. Consult a healthcare professional for personalised guidance.
How this tool works
This tool calculates your ideal body weight (IBW) using four clinical formulas developed between 1964 and 1983. Each formula uses height and sex to estimate a target weight. Devine (1974) is the most widely used in clinical settings for medication dosing. Robinson (1983) and Miller (1983) use slightly different coefficients. Hamwi (1964) adds a frame-size adjustment of plus or minus 10 percent. All formulas require height in inches; metric inputs are converted automatically. For heights below 5 feet, a standard adjustment of minus 2.3 kg per inch below 60 inches is applied and results are flagged as estimates. The recommended range spans from the lowest to the highest IBW across all four formulas, giving you a realistic band rather than a single number. BMI at each formula's IBW is shown for reference.
Worked example
A 5'10" (70 in) male gets: Devine 73 kg, Robinson 71 kg, Miller 70.3 kg, Hamwi 75 kg. The recommended range is approximately 70.3 to 75 kg (155 to 165 lb). With a large frame, the Hamwi value adjusts to 82.5 kg. If the person currently weighs 90 kg, the tool shows they are about 17.4 kg above the range midpoint.
Frequently asked questions
Which ideal weight formula is most accurate?
No single formula is universally best. Devine is the most widely used in clinical practice. For most people the four formulas produce results within 5 kg of each other -- the range itself is more useful than any single number.
Why do ideal weight formulas differ by sex?
Men typically have greater bone density and muscle mass than women at the same height, so male formulas use a higher base weight. The difference is around 4-5 kg at most heights.
Is ideal weight the same as a healthy BMI weight?
Not exactly. A BMI of 18.5-24.9 gives a healthy weight range based purely on height and weight. Clinical IBW formulas add frame-size context and were originally developed for medication dosing in hospitals, not consumer fitness targets. Both are useful reference points.