Hamwi Method Ideal Weight Calculator

The Hamwi method, from 1964, is the oldest of the common ideal-weight rules and the one most dietitians learned first. Enter your height and sex.

The Hamwi formula

Men: 48 kg for the first 5 ft, then 2.7 kg for each additional inch. Women: 45.5 kg for the first 5 ft, then 2.2 kg per additional inch. It is often quoted in pounds as 106 lb + 6 lb/inch (men) and 100 lb + 5 lb/inch (women).

Worked example

A man 5 ft 10 in tall (10 inches over 5 ft): 48 + 2.7 × 10 = 75 kg (165 lb). A woman the same height: 45.5 + 2.2 × 10 = 67.5 kg (149 lb).

How it compares

Hamwi has the steepest per-inch slope of the four, so it gives the highest number for tall people: at 5 ft 10 in it is 75 kg versus Miller's 70.3 kg, and by 6 ft 4 in the gap grows past 8 kg. For shorter people the four converge, and below about 5 ft 4 in Hamwi can fall below Miller. It was designed for quick bedside diabetes diet planning, not precision.

Ideal weight by height

Height	Devine	Robinson	Miller	Hamwi
5 ft 4 in, man	59 kg	60 kg	62 kg	59 kg
5 ft 10 in, man	73 kg	71 kg	70 kg	75 kg
6 ft 2 in, man	87 kg	83 kg	81 kg	91 kg
5 ft 4 in, woman	55 kg	56 kg	58 kg	54 kg
5 ft 8 in, woman	64 kg	63 kg	64 kg	63 kg

Figures rounded to the nearest kg. Your result above is exact for the height you entered.

The other ideal-weight formulas

Devine formula — the clinical default, and the parent calculator.
Robinson — A 1983 re-fit of Devine's constants — reads a little lighter than Devine at most heights.
Miller — Also 1983, with the gentlest per-inch slope — the four formulas fan out most at the extremes of height.
Healthy BMI range — Not a single number — the whole weight band that lands in a BMI of 18.5–24.9 for your height.

Use it with the other checks

A height-only formula cannot see muscle or fat. Read this figure next to your BMI, your body-fat percentage, and — if you are setting calories — your TDEE. To move toward a target weight, run a modest deficit or surplus with the calorie calculator.

Source: Hamwi GJ, 1964 (diabetes diet planning). BMI cut-offs: WHO.

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Frequently asked questions

Is the Hamwi method still used?

Yes, in clinical nutrition — it is fast to do in your head and widely taught. It is used to set a starting point for calorie and protein targets, then adjusted for frame size (±10%) and refined against the patient's actual intake and labs.

How do I apply the frame-size adjustment?

Wrap your thumb and index finger around the other wrist: if they overlap, small frame — subtract 10%; if they just touch, medium — no change; if they do not meet, large — add 10%. It is a crude proxy for skeletal width, so treat it as widening the estimate into a band, not a precise correction.

Why is Hamwi the heaviest formula for tall people?

Its 2.7 kg-per-inch term is the largest of the four. Devine (2.3), Robinson (1.9) and Miller (1.41) all add less per inch, so the taller you are, the further Hamwi pulls ahead.

Does Hamwi have a metric version?

The kilogram constants here (48 / 45.5 kg base, 2.7 / 2.2 kg per inch) are the direct conversion of the original pound figures (106 / 100 lb, 6 / 5 lb per inch). Height is still measured in inches over 5 ft either way.

Should I aim for my Hamwi weight?

It is a planning number, not a goal. Use it to sanity-check your weight and to seed a calorie target, then let your body-fat percentage, strength and health markers tell you whether to adjust.

Last reviewed: September 2026. Figures and formulas are checked against their published sources; see the site's data notes.