Ideal Weight Calculator
Ideal weight by four classic formulas
This free Ideal Weight Calculator shows what four long-established formulas suggest you should weigh for your height, side by side with the healthy BMI weight range for the same height. The Devine, Robinson, Miller and Hamwi formulas were each developed by doctors and pharmacists, mostly to guide medicine dosing, and each takes a slightly different view: a base weight for five feet of height, plus an allowance for every extra inch. Comparing all four, instead of trusting one magic number, gives a realistic band to think about rather than a single intimidating target.
That band matters, because there is honestly no single perfect weight for a height. Frame size, muscle mass, age, sex-specific body composition and overall health all shift what is right for an individual, and a trained athlete can be perfectly healthy above every figure shown here. Treat the results as an estimate only, not medical advice: they are a starting point for a conversation, not a verdict on your body. If you plan significant weight change, a doctor or dietitian who knows your history is the right guide. This tool runs fully in your browser, so the details you enter are never uploaded or stored.
How to use
- Select your sex, since the formulas use different base values.
- Enter your height in centimetres, measured without shoes.
- Click Calculate ideal weight to see the comparison table.
- Compare the four formulas with the healthy BMI range.
- Think of the overlap as a broad guide, not an exact prescription.
Frequently asked questions
Why do the four formulas give different answers?
They were published in different decades by different authors working from different patient data, and each adds a different amount of weight per inch of height. The spread between them, often a few kilograms, honestly reflects how approximate the whole idea of an ideal weight is.
Which formula should I trust most?
None of them individually. Devine is the most widely used in medicine, but the sensible approach is to look at the range the four create together with the BMI healthy band, and to weigh other factors, like muscle and waist size, alongside.
What if I am shorter than five feet?
The formulas still work: the allowance per inch is subtracted instead of added below five feet. Results for very short or very tall heights are less well supported by the original research, so treat them with extra caution.
Is the BMI range better than the formulas?
It answers a slightly different question. The BMI band shows every weight that counts as a healthy BMI at your height, which is a wide window. The formulas aim at a single suggested point inside or near that window. Both are guides, and neither replaces personal medical advice.