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Health & Fitness · Body Metrics Formula verified

Ideal Weight Calculator

Enter your height and sex to see a reference body weight from four widely published formulas, plus their average — they don't always agree, and this shows exactly how much they differ for your height.

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Average of the four formulas
72.3 kg
Devine
73.0 kg
Robinson
71.0 kg
Miller
70.3 kg
Hamwi
75.0 kg

Step-by-step proofCheck by hand
These are population-based reference formulas, not a personal target. They were originally developed for medical drug-dosing calculations, not as fitness or health goals, and none of them account for muscle mass, frame size, body composition or individual health. A healthy weight for you may fall outside every range shown here. For a personal target, talk with a qualified healthcare provider.

How each formula is calculated

Every formula here is a straight line: a fixed base weight for someone 5 feet (60 inches) tall, plus a fixed amount per inch above that, with different constants for men and women. They were developed independently between 1964 and 1983, mostly for calculating medication doses — not as fitness targets — which is why they don't fully agree with each other.

The formulas (male / female, per inch over 5 ft)

Devine: 50.0 / 45.5 kg + 2.30 kg/in  ·  Robinson: 52.0 / 49.0 kg + 1.90 / 1.70 kg/in
Miller: 56.2 / 53.1 kg + 1.41 / 1.36 kg/in  ·  Hamwi: 48.0 / 45.5 kg + 2.70 / 2.20 kg/in

Worked example

A man 178 cm (5'10") tall: Devine = 50.0 + 2.30 × 10 = 73.0 kg, Robinson = 52.0 + 1.90 × 10 = 71.0 kg, Miller = 56.2 + 1.41 × 10 = 70.3 kg, and Hamwi = 48.0 + 2.70 × 10 = 75.0 kg — an average of 72.3 kg across all four.

Frequently asked questions

Why do the four formulas give different answers?
Each one was developed independently, years apart, from different population data and for a different original purpose — mostly calculating medication doses, not describing a fitness ideal. Devine (1974) and Hamwi (1964) tend to run lower for taller heights, while Robinson (1983) and Miller (1983) run a bit higher, so the spread between them at any given height is a genuine disagreement between methods, not an error.
Should I aim for the average of the four?
The average is shown as a single reference point, not a recommended target. None of these formulas account for muscle mass, bone structure or body composition, so two people of the same height and sex can have very different healthy weights. Treat every number here as a rough population-level reference, not a personal goal.
How is this different from the BMI Calculator?
BMI works backward from your actual weight and height to a single index number and a broad category. These formulas instead work forward from height alone (plus sex) to a reference weight, using older clinical formulas rather than the BMI scale. See the BMI Calculator for the index-based approach.
Sources and method
  • Devine formula — B.J. Devine, "Gentamicin therapy," Drug Intelligence & Clinical Pharmacy, 1974.
  • Robinson formula — J.D. Robinson et al., "Determination of ideal body weight for drug dosage calculations," American Journal of Hospital Pharmacy, 1983.
  • Miller formula — D.R. Miller et al., "Ideal body weight," American Journal of Hospital Pharmacy, 1983.
  • Hamwi formula — G.J. Hamwi, "Therapy: changing dietary concepts," in Diabetes Mellitus: Diagnosis and Treatment, American Diabetes Association, 1964.
Last reviewed: 20 Sep 2026 Sources last verified: 20 Sep 2026 Results use the assumptions explained on this page. Report an error How we check calculations

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