Ideal Weight Calculator
Compare Devine, Robinson, Miller, and Hamwi ideal-weight formulas side by side.
How do ideal weight formulas compare?
Ideal-weight formulas estimate an adult reference weight from height and sex, but Devine, Robinson, Miller and Hamwi use different constants and can disagree.
Formula: Adult ideal-weight formulas start with a base weight at 5 feet tall, then add a sex-specific amount for each inch above 5 feet. This calculator shows Devine, Robinson, Miller, and Hamwi side by side.
What this calculator does
Enter height and sex used by the formulas to see four adult ideal-weight estimates, the formula range, and an average for comparison.
Use it to turn Units, Sex used by the formula, Height, Height (feet), and the other shown inputs into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this health & fitness calculation.
Inputs and what they mean
- Units
- — choice value.
- Sex used by the formula
- — choice value.
- Height
- — number value.
- Height (feet)
- — number value.
- Height (inches)
- — number value.
How to use it
- Choose the unit system and formula options that match your inputs.
- Enter the measurements requested by the calculator.
- Review the result, breakdown, worked example, and limitations before using the estimate.
Formula
Devine: male = 50 kg + 2.3 kg per inch over 5 ft; female = 45.5 kg + 2.3 kg per inch over 5 ft.
Robinson: male = 52 kg + 1.9 kg per inch over 5 ft; female = 49 kg + 1.7 kg per inch over 5 ft.
Miller: male = 56.2 kg + 1.41 kg per inch over 5 ft; female = 53.1 kg + 1.36 kg per inch over 5 ft.
Hamwi: male = 48 kg + 2.7 kg per inch over 5 ft; female = 45.5 kg + 2.2 kg per inch over 5 ft. For heights below 5 feet, the base value is used instead of subtracting below the formula's anchor point.
Adult ideal-weight formulas start with a base weight at 5 feet tall, then add a sex-specific amount for each inch above 5 feet. This calculator shows Devine, Robinson, Miller, and Hamwi side by side.
Inputs used: Units, Sex used by the formula, Height, Height (feet), Height (inches).
Worked example
Female, 5 ft 6 in
- Convert 5 ft 6 in to total inches: 5 × 12 + 6 = 66 inches.
- Find inches above 5 ft: 66 − 60 = 6 inches.
- Devine female result: 45.5 + 2.3 × 6 = 59.3 kg.
- Robinson, Miller, and Hamwi are calculated the same way with their own constants, then the four values are averaged.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- These adult formulas do not account for muscle mass, body frame, pregnancy, disability, or clinical context.
- The formulas are anchored at 5 feet tall; for shorter heights, this calculator keeps the base value rather than extrapolating downward.
- The average is only a summary of four formulas, not a recommended target weight.
- Estimate for informational purposes only; not medical advice, diagnosis or treatment.
- Inputs outside the supported range are rejected rather than forced into a result.
Common questions
How do ideal weight formulas compare?
Ideal-weight formulas estimate an adult reference weight from height and sex, but Devine, Robinson, Miller and Hamwi use different constants and can disagree. Check the formula, example, and limitations on this page before using the result for a real health & fitness decision.
Why do the ideal-weight formulas disagree?
They were created from different historical assumptions and intended uses. Showing them side by side is more honest than pretending there is one exact ideal weight.
Is ideal weight the same as a healthy weight?
No. These formulas do not evaluate body composition, waist measurements, lab results, age, ethnicity, or medical history. A healthy weight range for a person can be broader than these formula outputs.
Can children use this calculator?
No. These equations are adult formulas and are not appropriate for children or teens. Pediatric growth and weight assessment should use age- and sex-specific clinical growth charts.
How do I use the Ideal Weight Calculator?
Enter the required values for Units, Sex used by the formula, Height, Height (feet), Height (inches). The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Ideal Weight Calculator use?
Adult ideal-weight formulas start with a base weight at 5 feet tall, then add a sex-specific amount for each inch above 5 feet. This calculator shows Devine, Robinson, Miller, and Hamwi side by side. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
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