Ideal Weight Calculator — FAQ

Enter your height and sex, and the tool computes what each of the four classic formulas (Devine, Robinson, Miller, Hamwi) produces for those inputs, alongside the healthy-weight range from BMI (18.5–24.9) for your height. All five results are shown side by side so you can see how much they differ — no single number is presented as a target.

Because the formulas disagree — sometimes by several kilograms — and none is definitive. Showing the spread is more honest than implying one correct answer. The range across methods gives a better sense of the genuine uncertainty in these estimates.

The tool uses four classic ideal body weight formulas: Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964). It also shows the BMI healthy-weight range (18.5–24.9 × height²) as a fifth reference point. Each formula card shows a brief note on its origin and context.

Not really. Most of these formulas are decades old and several — including Devine and Hamwi — were originally developed for medication dosing calculations, not as personal health targets. Health is far better understood as a range across many factors, not a single number on a scale.

They are simple linear equations based only on height. They cannot distinguish muscle from fat, account for frame size, bone density, age, or individual variation. This is one of their core limitations — a heavily muscled person and a sedentary person of the same height get the same formula result.

Yes. You can enter your height in centimetres or in feet and inches, and choose whether to see results in kg or lb. The formulas produce identical results regardless of which unit system you use — the tool handles the conversion automatically.

Please don't treat any of these as a target. Use the range as general context only. For anything about your personal weight or health, rely on a registered dietitian or physician rather than any formula — they can account for the factors these equations ignore.

No. Your height and sex are processed entirely in your browser and are never stored or sent to any server, keeping your information completely private.

Yes. The tool is fully responsive — the comparison panel stacks vertically on small screens so nothing overflows and all results remain easy to read on any device without horizontal scrolling.

Please don't treat any formula result as a target to aim for. These are historical reference estimates, not medical or dietary prescriptions. For personal guidance about your weight or health, consult a doctor or registered dietitian. If you find yourself preoccupied with your weight or body, consider reaching out to a qualified professional for support.