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Ideal Weight Calculator

Estimate your ideal body weight from your height and sex using the Robinson, Miller, Devine, and Hamwi formulas, alongside the healthy weight range for your height.

Gender
years

These formulas apply to adults; age does not change the result.

ft
in

Healthy weight range (BMI 18.5–25)

128.9 – 174.2 lb

Ideal weight by formula

FormulaIdeal Weight
Robinson formula156.5 lb
Miller formula155.0 lb
Devine formula160.9 lb
Hamwi formula165.3 lb
Healthy weight range (BMI 18.5–25)128.9 – 174.2 lbView results

This calculator estimates your ideal body weight from your height and sex using four well-known formulas — Robinson, Miller, Devine, and Hamwi — and shows the healthy weight range (BMI 18.5–25) for your height. No body weight input is needed; the result depends only on height and sex.

Formula

Every formula follows the same shape — a base weight at 5 feet plus an increment for each inch above 5 feet:

ideal weight = base + per_inch × (height_in_inches − 60)

The base weights and per-inch increments (in kg) are:

FormulaMen base / per inchWomen base / per inch
Hamwi (1964)48.0 kg / 2.7 kg45.5 kg / 2.2 kg
Devine (1974)50.0 kg / 2.3 kg45.5 kg / 2.3 kg
Robinson (1983)52.0 kg / 1.9 kg49.0 kg / 1.7 kg
Miller (1983)56.2 kg / 1.41 kg53.1 kg / 1.36 kg

The healthy weight range applies the WHO healthy BMI band (18.5–25) to your height: weight = BMI × height².

IBW formulas ignore body fat, muscle, and frame size. Treat the numbers as a reference range, not a strict target.

Examples

Man, 180 cm

180 cm is about 70.9 inches, or 10.9 inches over 5 feet. The Devine estimate is 50 + 2.3 × 10.9 ≈ 75.0 kg, Robinson ≈ 72.6 kg, Miller ≈ 71.5 kg, and Hamwi ≈ 77.3 kg. The healthy weight range for this height is about 59.9–81.0 kg.

Woman, 5 ft 5 in

5 ft 5 in is 65 inches, or 5 inches over 5 feet. The Robinson estimate is 49 + 1.7 × 5 = 57.5 kg (about 126.8 lb), with the other formulas nearby.

Frequently asked questions

What is ideal body weight (IBW)?
Ideal body weight is an estimate of a healthy weight for a given height and sex. The classic formulas were originally developed to help calculate medication dosages, not as strict health targets. Because they only use height and sex, they don't account for body composition, frame size, or muscle mass.
Which ideal weight formula is best?
There's no single "best" formula — they were derived from different populations and give slightly different numbers. The Devine formula is the most widely used in clinical settings (especially for drug dosing). The Robinson and Miller formulas are modern modifications of Devine. We show all four so you can see the range.
How is height used in the formulas?
Each formula starts from a base weight at 5 feet (60 inches) and adds a set amount of weight for every inch above that. For example, the Devine formula for men is 50 kg + 2.3 kg per inch over 5 feet, so a 5 ft 10 in man gets 50 + 2.3 × 10 = 73 kg.
Should I aim for my ideal body weight?
Not necessarily. IBW is a rough reference, not a goal. Very fit, muscular people often weigh more than their IBW while being perfectly healthy. The healthy weight range (BMI 18.5–25) shown alongside the formulas is usually a more practical guide.
Do these formulas work for children?
No. They apply to adults. For children and teens (ages 2–20), weight status is assessed against age- and sex-specific CDC growth-chart percentiles rather than these adult formulas.

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