By Zencalcy Editorial TeamLast reviewed About us
Ideal body weight formulas estimate a reference weight for a given height. They were built for clinical dosing and insurance tables, not as personal targets. This calculator shows four common formulas side by side and compares them with the weight range linked to a healthy BMI.
Compare four ideal-weight formulas and a healthy BMI range.
Devine: men 50 + 2.3 × in over 5 ft; women 45.5 + 2.3 × in over 5 ft Robinson: men 52 + 1.9 × in over 5 ft; women 49 + 1.7 × in over 5 ft Miller: men 56.2 + 1.41 × in over 5 ft; women 53.1 + 1.36 × in over 5 ft Hamwi: men 48 + 2.7 × in over 5 ft; women 45.5 + 2.2 × in over 5 ft
For heights below 5 ft the same per-inch increment is subtracted. These formulas ignore frame size, age and body composition, so they can be misleading for athletes and older adults. The BMI range is a population screening band, not an individual prescription.
| Symbol | Meaning |
|---|---|
| IBW | Ideal body weight estimate in kilograms. |
| BMI | Body mass index, weight ÷ height². |
175 cm is 68.9 inches, or 8.9 inches over 5 ft. Devine: 50 + 20.5 = 70.5 kg. Robinson: 52 + 16.9 = 68.9 kg. Miller: 56.2 + 12.5 = 68.7 kg. Hamwi: 48 + 24.0 = 72.0 kg. The 18.5–24.9 BMI range for 1.75 m is 56.7–76.3 kg.
The word ideal is misleading. These formulas were created for practical purposes: insurance tables in the early twentieth century and drug dosing later on. They describe the average weight associated with a height in a particular population, not the weight at which an individual will be healthiest. Two people of the same height can both be healthy at weights that differ by ten kilograms because muscle mass, frame size, age and fat distribution differ. The BMI range is wider and more useful for a conversation, but it too is a screening tool. A better approach is to combine a healthy weight range with waist circumference, blood pressure, glucose and how you function. If you are choosing a goal, pick a range you can maintain with sustainable habits rather than a single number from a 1974 equation.
Continue with the ABSI Calculator (A Body Shape Index), Adjusted Body Weight Calculator, or the BAI Calculator (Body Adiposity Index) — or browse more body measurements tools and all health calculators.
Also see the Body Fat Calculator.
None is universally best. Devine is common in clinical dosing, Robinson tends to give lower values, and Hamwi is the oldest. The spread between them shows how approximate the concept is.
Every result is a screening estimate from published anthropometric equations, not a diagnosis or a measurement of body composition. Tape measurements should be taken snugly against the skin without compressing it, at the landmarks named in each tool. Equations were derived in specific populations and can be less accurate for athletes, older adults, children, pregnant people and people with significant oedema.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026