Health
Ideal weight calculator
Height and sex are enough: see the ideal weight by five different formulas, side by side on one scale with the healthy weight range and your current weight.
Why the formulas disagree
There is no single ideal weight. The common formulas are straight lines fitted to population data: Devine (1974) was devised for drug dosing, Robinson and Miller (1983) recalibrated it on newer data, and Hamwi (1964) was a dietitians' rule of thumb. Lorentz, popular in continental Europe, starts from height in centimetres minus 100.
For a man of 180 cm (5′11″) the formulas give roughly 72 to 78 kg (159–172 lb), while the healthy BMI range runs from 60 to 81 kg (132–178 lb). The chart puts everything on one scale: the formulas almost always fall inside the healthy range, which remains the sounder reference.
Below about 152 cm (5 ft) the inch-based formulas become extrapolations and are not shown. None of them accounts for build, muscle mass or age.
Common mistakes
- Taking one number as an exact target instead of a range.
- Using the male formula for a woman: at the same height the female values are lower.
- Ignoring build: a very muscular person can be healthy above the formula values.
Frequently asked questions
Which ideal weight formula is most accurate?
None is accurate for everyone: they are all averages. Robinson and Miller are the most recent; for a realistic range, look at the healthy BMI range.
What is the Devine formula?
Men: 50 kg + 2.3 kg per inch over 5 feet. Women: 45.5 kg + 2.3 kg per inch over 5 feet.
Does ideal weight change with age?
The formulas ignore age, but body composition changes over the years, which is why the healthy BMI range is the more flexible reference.
How this calculation works
With h the inches over 60: Devine 50 + 2.3·h (women 45.5); Robinson 52 + 1.9·h (49 + 1.7·h); Miller 56.2 + 1.41·h (53.1 + 1.36·h); Hamwi 48 + 2.7·h (45.5 + 2.2·h), in kilograms. Lorentz: H − 100 − (H − 150)/4 for men and /2 for women, H in centimetres. Healthy range: BMI 18.5 to 24.9.
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