Reference Weight Range Calculator
Weight ranges from the standard clinical formulas, with a clear account of what they can and cannot tell you.
Formula
Devine, Robinson, Miller and Hamwi formulas, plus the BMI 18.5–25 range
Tips
- The four formulas are shown side by side deliberately: they routinely disagree by five kilograms or more for the same height, which is the clearest evidence that none of them is authoritative.
- Devine and Hamwi were written to calculate drug dosages, not to advise anyone on their weight. They were never intended for this use.
- None of these formulas accounts for build, muscle mass, age or ethnicity. A muscular person will read as "over" every one of them while being perfectly healthy.
- The BMI range is broad on purpose. Health outcomes vary far more within it than the range boundaries suggest, and the edges are not cliffs.
- There is no single correct weight for a given height. If you are trying to decide what weight is right for you, that is a conversation with a clinician who knows your history, not an output of a formula.
Frequently asked questions
Which formula should I trust?
None of them, individually. They are shown together to make the disagreement visible. If you need a clinically meaningful assessment, a GP will consider blood pressure, blood markers, fitness, family history and how you actually feel — none of which a height-based formula can see.
I am outside every range. Is that a problem?
Not necessarily, and not something a calculator can determine. Athletes, older adults and people with different builds sit outside these ranges routinely while being healthy. If you are concerned, that is worth raising with a GP rather than resolving with arithmetic.