Ideal weight calculator — four formulas compared
Compare four height-based weight estimates and the adult BMI reference range. Use the results to understand the formulas, rather than to choose a weight you should reach.
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These formulas use height and sex and can give different answers for the same person. They do not account for build, age or body composition.
Neither a formula result nor the BMI range is a personal weight goal or a diagnosis.
How to use
- Enter height and units. Use centimetres or feet and inches; current weight is not needed.
- Select the formula’s sex option. Each equation uses different constants for the two options.
- Compare the rows. At 5 ft 10 in (177.8 cm), the male option gives 73.0 kg for Devine, 71.0 kg for Robinson, 70.3 kg for Miller and 75.0 kg for Hamwi.
Questions
Why are there four answers?
Each formula starts with a different base weight at 5 feet and adds a different amount per extra inch. Agreement between them would not establish an individual ideal weight; disagreement reflects their different rules.
What does the BMI range add?
It shows the weights corresponding to BMI 18.5–24.9 at the entered height. Like the individual formulas, it does not assess body composition, medical history or pregnancy. It is an adult reference, not a goal or a child-growth assessment.
What happens below 5 feet?
The equations subtract weight for each inch below 5 feet, and the calculator prevents a negative result. Those outputs should not be treated as recommended weights, particularly at very short heights.
How it works and sources
How this is calculated
The tool compares four named height-and-sex formulas: Devine (1974), Robinson (1983), Miller (1983) and Hamwi (1964). Each starts with a weight at five feet and adds an amount for each inch above that height. It also shows the weights corresponding to adult BMI values of 18.5 and 24.9. The WHO source supports the BMI comparison, not the four formula coefficients.
What the calculation assumes
- The formulas use only height and the selected sex equation. They do not account for build, age, body composition or medical circumstances.
- These are adult reference calculations, not growth charts or pregnancy weight targets.
Where the result has limits
- Below five feet (152.4 cm), the tool subtracts weight using the same coefficients. That extrapolation is not established by the source listed here and can give misleading results.
- Primary sources for the four named formulas are not included in this entry and need to be checked. The displayed names and years do not establish that every implementation detail is supported.
- Different formulas give different answers. Neither a single estimate nor the BMI reference range determines the right weight for you.
Sources
- A healthy lifestyle — WHO recommendations (BMI classification) World Health Organization
Sources last checked 30 July 2026.
These estimates are general information, not medical advice.
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