Ideal Weight Calculator

Calculate ideal body weight using Robinson, Miller, Devine, and Hamwi formulas. Compare results with healthy BMI range.

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Ideal Body Weight Formulas

Several formulas estimate ideal body weight (IBW) based on height. All were originally designed for drug dosing but are widely used as general health references.

Formula Summary

Formula	Male (kg)	Female (kg)
Robinson (1983)	52 + 1.9 per inch over 5'	49 + 1.7 per inch over 5'
Miller (1983)	56.2 + 1.41 per inch over 5'	53.1 + 1.36 per inch over 5'
Devine (1974)	50 + 2.3 per inch over 5'	45.5 + 2.3 per inch over 5'
Hamwi (1964)	48 + 2.7 per inch over 5'	45.5 + 2.2 per inch over 5'

Healthy BMI Range

The World Health Organization defines a healthy BMI as 18.5–24.9. The calculator converts this to a weight range for your height using: Weight = BMI × height(m)².

Limitations

No body composition: These formulas don't distinguish muscle from fat. A muscular 5'10" person may be perfectly healthy at 200 lbs
Frame size ignored: People with larger bone structures naturally weigh more
Population bias: Formulas were developed primarily from Caucasian populations and may not apply equally to all ethnicities
Height below 5 feet: All formulas use inches over 5 feet as the variable — results for shorter heights are extrapolations

Better Alternatives

Body fat percentage: Healthy ranges are 10–20% for men, 18–28% for women. Use our Body Fat Calculator
BMI: While imperfect, BMI combined with waist circumference gives a reasonable health assessment. See our BMI Calculator
Waist-to-height ratio: Keep waist below half your height. Simple, effective, and accounts for central obesity

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On conv.awajis.com

Pounds to Kilograms Convert a target weight to metric.

Frequently Asked Questions

What is the ideal weight for a 5 ft 7 in woman?

The Devine formula gives about 61.6 kg (136 lb) for a woman who is 5 ft 7 in (168 cm): 45.5 + (2.3 x 7 inches over 5 ft) = 61.6 kg. The healthy BMI range of 18.5 to 24.9 at that height spans about 52 to 70 kg, so the formula value is a midpoint, not a strict target.

Which ideal weight formula is most accurate?

The Robinson formula (1983) is generally considered the most accurate for the general population. The other common formulas are Miller (1983), Devine (1974) and Hamwi (1964). None of them account for muscle mass, frame size or body composition, and all four were originally developed for drug dosing rather than health assessment.

Why do ideal weight formulas give different results?

Each formula was built from different study populations and methods, so the same height produces several answers. The spread between Robinson, Miller, Devine and Hamwi is best read as a target zone. The formulas also use only height and sex, so age-related changes in muscle and bone are not reflected.

Is ideal weight accurate for muscular people?

No. The formulas can badly underestimate a healthy weight for muscular people, because muscle is denser than fat and the equations use only height and sex. A bodybuilder who is 5 ft 10 in may weigh over 200 lb at a healthy body fat level. Body fat percentage is a better measure for athletes.