CALCULATOR 08

Ideal Weight Calculator

Four classic ideal-weight formulas and the BMI healthy range for your height—estimates, not targets.

Ideal weight estimates

Choose the sex used in the formulas.

For general information only; not medical advice. Consult a qualified professional before making health decisions.

How this is calculated

x = height in inches − 60   (results in kg)

Formulas

Robinson (1983)  men 52 + 1.9x     women 49 + 1.7x
Miller (1983)    men 56.2 + 1.41x  women 53.1 + 1.36x
Devine (1974)    men 50 + 2.3x     women 45.5 + 2.3x
Hamwi (1964)     men 48 + 2.7x     women 45.5 + 2.2x

BMI healthy range

18.5 × height (m)²  to  24.9 × height (m)²

Below 152.4 cm (5 ft), the formulas aren't reliable, so only the BMI range is shown.

Sources

Devine BJ (1974); Robinson JD et al. (1983); Miller DR et al. (1983); Hamwi GJ (1964) — ideal body weight formulas.
World Health Organization, Body mass index (BMI) classification for adults.

Where the formulas come from

These equations weren't designed as personal goals. Hamwi's 1964 formula was a clinical rule of thumb, and Devine's 1974 version was created to help calculate drug doses. In 1983, Robinson and Miller each re-fitted the same style of equation to population height and weight data. All four start from a base weight at 5 ft and add a fixed amount for every inch above.

Read more about the Ideal Weight calculator

Why the formulas disagree

Each formula was built from different data and for a different purpose, so their answers can differ by several kilograms, and the gap widens the taller you are. None of them considers age, frame size, muscle or body fat. That's why the calculator shows all four as a range next to the BMI healthy range, rather than picking one number.

Estimates, not targets

A healthy weight is a range, and for many people it sits outside these formulas' answers—particularly for people with more muscle. How you feel, your waist size, body fat, fitness, blood pressure and blood sugar all say more about your health than hitting a formula's number.

Shorter heights

The formulas were built around heights of 5 ft and above. Below 152.4 cm they extrapolate backwards and quickly stop making sense, so the calculator hides them and shows only the BMI healthy range.

Frequently asked questions

Which ideal weight formula is best?

None is clearly best. Devine is the most widely used in medicine, mainly for drug dosing. Looking at the range across all four, alongside the BMI healthy range, is more useful than any single formula.

Why don't the formulas consider age or muscle?

They were designed as quick clinical estimates from height and sex alone. They can't account for muscle, frame size or age, which is why their results are estimates, not targets.

Is ideal weight the same as a healthy weight?

No. A healthy weight is a range that depends on your body composition, fitness and health markers. The BMI healthy range is a broader, more flexible guide.

Why are the formulas hidden for people under 5 ft?

The formulas start at 5 ft (152.4 cm). Below that, they give unreliable results, so only the BMI healthy range is shown.