Ideal Weight Calculator is a free tool that compares four classic ideal-weight formulas — Devine, Robinson, Miller and Hamwi — for your height, and shows the range where they agree. That overlap is the honest answer; any single number would be false precision. Nothing is uploaded.
How to find a healthy weight range
- Pick Metric or Imperial and your Sex.
- Enter your Height.
- Read The agreement first — the band all four formulas share.
- Compare the four rows to see how much the answer depends on who you ask.
A 180 cm man, four answers
Devine says 75.1 kg, Robinson 72.6, Miller 71.5 and Hamwi 77.3 — a spread of nearly six kilograms from the same height. The overlap sits roughly 72 to 77 kg, and that band is more trustworthy than any of its members: each formula was fitted to a different population decades apart, so consensus filters their individual biases. Check where you actually stand with the BMI Calculator, which judges the weight you have rather than prescribing one.
Why height alone can never finish the job
None of these formulas has ever seen your shoulders, your training history or your frame — a rugby player and a programmer of equal height get equal prescriptions. That is why this page ends where body composition begins: take the tape-measure test in the Body Fat Percentage Calculatorbefore turning any of these numbers into a goal.
Frequently asked questions
Which formula should I trust?
Devine is the clinical default — drug dosing is still based on it. The other three are refinements that disagree by a few kilograms, which is itself the message: “ideal” is a range, not a number.
Why do the four answers differ?
Each was fitted to different populations decades apart: Devine (1974) for drug dosing, Robinson (1983) and Miller (1983) from insurance data, Hamwi (1964) for clinical use. Where they overlap — usually a 3–5 kg band — is the honest answer.
Does frame size or muscle change this?
Yes, and none of these formulas know about either. A large-framed or muscular person sits healthily above the top line, which is why this page pairs with a body-fat reading rather than replacing it.
Is this medical advice?
No. These are decades-old population formulas applied to one height. Useful as a sanity anchor, useless as a verdict — weight goals deserve a professional who can see you.
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