Ideal Weight Calculator
Your ideal weight by four medical formulas, and the healthy BMI range for your height.
Good to know. The famous formulas were written for dosing medicine in the 1970s, not for mirrors. A range is the honest answer.
Not medical advice. A general estimate for healthy adults.
How it works
In plain words
Each formula starts from a weight at 5 feet (152.4 cm) and adds a fixed amount for every inch above it, with different numbers for men and women. The healthy range is the weight that gives a BMI between 18.5 and 24.9 at your height.
The formula
Devine: men 50 kg + 2.3 kg per inch over 5 ft; women 45.5 kg + 2.3 kg Robinson: men 52 + 1.9; women 49 + 1.7 Miller: men 56.2 + 1.41; women 53.1 + 1.36 Hamwi: men 48 + 2.7; women 45.5 + 2.2 healthy range = 18.5 to 24.9 × height (m)²
Worked example
A man 178 cm tall is 70.08 inches, 10.08 over 5 ft. Devine: 50 + 2.3 × 10.08 = 73.2 kg. The healthy BMI range at that height is 58.6 to 78.9 kg.
Sources
- Devine, Gentamicin therapy, Drug Intelligence and Clinical Pharmacy, 1974 The Devine formula.
- Robinson et al., Determination of ideal body weight for drug dosage calculations, American Journal of Hospital Pharmacy, 1983 The Robinson formula.
- Miller et al., Determination of ideal body weight, American Journal of Hospital Pharmacy, 1983 The Miller formula.
- World Health Organization, body mass index classification The healthy range of 18.5 to 24.9.
Sources checked September 30, 2026. 3 automated tests check its answers on every change.
About the ideal weight calculator
There is no single ideal weight for a height. What exists are formulas that give a reasonable target, and a healthy range. This calculator shows both, so you can see how much they agree.
The best-known formula, by B. J. Devine, was published in 1974 to work out doses of medicines that depend on body size, and it is still used for that in hospitals. Robinson, Miller and Hamwi published similar formulas with slightly different numbers. All four start from a weight at 5 feet tall and add a fixed amount per inch, which is why they only work for adults of roughly average build.
The healthy BMI range is the other common guide: a body mass index between 18.5 and 24.9. It covers a wide band, often 20 kg or more, because healthy people come in different builds. For a muscular person, weight above the range may be perfectly healthy; for someone with little muscle, a weight inside it can still mean too much body fat.
Use these numbers as a starting point for a conversation, not a verdict. Waist size, body fat percentage, fitness, blood pressure and how you feel say more about health than any weight formula. If you want to change your weight, a doctor or dietitian can help you set a target that suits you.
Questions people ask
What is my ideal weight for my height?
By the Devine formula, 50 kg plus 2.3 kg per inch over 5 feet for men, 45.5 kg plus 2.3 kg for women. At 178 cm, that is 73.2 kg for a man.
Which ideal weight formula is best?
None is clearly best. Devine is the most widely used, mainly in medicine. The healthy BMI range is a better guide for most people.
Does ideal weight depend on age?
The formulas ignore age. Some studies suggest a slightly higher BMI is fine in older adults, so check with a doctor.