Which formula is used?

The Devine formula: 50 kg + 2.3 kg per inch over 5 feet for men, and 45.5 kg + 2.3 kg per inch over 5 feet for women. It’s the most widely used clinical estimate of ideal body weight by height.

Why was the Devine formula created?

It was published in 1974 by pharmacist Ben J. Devine to standardize medication dosing by body size, not as a dieting target. It stuck because it’s simple, and it remains common in clinical settings today — but its origin is worth remembering when you interpret the number.

Why do other sites show a different ideal weight?

Several formulas exist — Hamwi (1964), Robinson (1983), and Miller (1983) are the usual alternatives — and each uses slightly different base weights and per-inch increments. Results typically differ by a few kilograms. None is more “correct”; they’re different conventions.

Is ideal weight the same as a healthy weight?

No. Healthy weight is a range, not a point. For example, at 180 cm the WHO normal BMI band (18.5–24.9) spans roughly 60 to 81 kg — the Devine estimate of 75 kg is just one point inside it. You can be perfectly healthy well away from the formula’s number.

What if I’m shorter than 5 feet (152.4 cm)?

The formula only adds weight for height above 5 feet, so this calculator returns the base value — 50 kg for men, 45.5 kg for women — at or below 152.4 cm. Devine’s equation was never well calibrated for short statures, so treat results there with extra caution.

Should I try to reach exactly this weight?

No. The formula ignores muscle mass, frame size, age, and body composition, so a muscular or large-framed person can be healthy well above it. If you’re considering a significant weight change, set the target with a doctor or dietitian rather than a formula.

No — the calculation happens entirely in your browser. Your height and sex are never sent to a server.

Ideal Weight Calculator

Estimate your ideal body weight for your height.

Runs in your browser — files never leave your device

HeightcmSex

Ideal weight

75 kg

How it works

“Ideal body weight” is a clinical reference weight estimated from height and sex. This calculator uses the Devine formula, published in 1974 for calculating medication doses and still the standard ideal-weight equation in medicine. It was never designed as a cosmetic or fitness target — it’s a reference point.

The formula: men: 50 kg + 2.3 kg for every inch of height over 5 feet; women: 45.5 kg + 2.3 kg per inch over 5 feet. The tool converts your height from centimeters to inches (dividing by 2.54), counts only the inches above 60 (5 feet = 152.4 cm), and rounds the result to one decimal place. Heights at or below 152.4 cm simply return the base weight.

Worked example: a man 180 cm tall. 180 ÷ 2.54 ≈ 70.87 inches, which is 10.87 inches over 5 feet. Then 2.3 × 10.87 ≈ 25.0 kg, and 50 + 25.0 = 75 kg — the value the tool displays. A woman of the same height starts from 45.5 kg instead and gets 70.5 kg.

Interpret the number as a mid-range anchor, not a finish line. Healthy weights for any height form a band: at 180 cm, the WHO normal BMI range alone spans roughly 60 to 81 kg. If your weight sits far from the Devine estimate, that’s a prompt to look at the fuller picture — body composition, waist size, fitness, blood work — not proof that anything is wrong.

Limitations: the formula considers nothing but height and sex. It ignores muscle mass, bone structure, age, and ethnicity, and rival formulas (Robinson, Miller, Hamwi) put the “ideal” a few kilograms away. Use it as general guidance only — not medical advice; a clinician can help you decide what a realistic, healthy weight looks like for you.

Frequently asked questions

Which formula is used?: The Devine formula: 50 kg + 2.3 kg per inch over 5 feet for men, and 45.5 kg + 2.3 kg per inch over 5 feet for women. It’s the most widely used clinical estimate of ideal body weight by height.
Why was the Devine formula created?: It was published in 1974 by pharmacist Ben J. Devine to standardize medication dosing by body size, not as a dieting target. It stuck because it’s simple, and it remains common in clinical settings today — but its origin is worth remembering when you interpret the number.
Why do other sites show a different ideal weight?: Several formulas exist — Hamwi (1964), Robinson (1983), and Miller (1983) are the usual alternatives — and each uses slightly different base weights and per-inch increments. Results typically differ by a few kilograms. None is more “correct”; they’re different conventions.
Is ideal weight the same as a healthy weight?: No. Healthy weight is a range, not a point. For example, at 180 cm the WHO normal BMI band (18.5–24.9) spans roughly 60 to 81 kg — the Devine estimate of 75 kg is just one point inside it. You can be perfectly healthy well away from the formula’s number.
What if I’m shorter than 5 feet (152.4 cm)?: The formula only adds weight for height above 5 feet, so this calculator returns the base value — 50 kg for men, 45.5 kg for women — at or below 152.4 cm. Devine’s equation was never well calibrated for short statures, so treat results there with extra caution.
Should I try to reach exactly this weight?: No. The formula ignores muscle mass, frame size, age, and body composition, so a muscular or large-framed person can be healthy well above it. If you’re considering a significant weight change, set the target with a doctor or dietitian rather than a formula.
Is my data uploaded?: No — the calculation happens entirely in your browser. Your height and sex are never sent to a server.

Ideal Weight Calculator

How it works

Frequently asked questions

Related tools