Enter your sex and height to see a healthy weight range for your height, alongside four classic clinical “ideal weight” formulas. There’s no single correct number — the formulas disagree by a few kilograms — so the tool shows them together as a guide, not a target. It runs entirely in your browser.
Choose your sex and enter your height.
These are educational estimates based on height and sex only. They ignore muscle, frame and age, and are not personal weight goals. Ask a healthcare professional for individual advice.
How it works
The headline figure is the weight range for a BMI of 18.5–24.9 at your height — the same healthy band the BMI calculator uses, and the most defensible answer to “what should I weigh?”. Below it, four formulas from medical literature (Devine, Robinson, Miller, Hamwi) each give a single number based on height above five feet, adjusted for sex.
These formulas were originally designed to estimate medication doses, not to set personal goals, and they take no account of muscle, frame size or age. That’s why they differ from one another and why the BMI range is broader — real healthy weights span a range, not a point.
Practical examples
A 175 cm man
The Devine formula gives about 70.5 kg, Robinson about 68.9 kg and Hamwi about 72 kg. The healthy BMI range for that height is roughly 56.7–76.2 kg — every formula sits inside it.
A 165 cm woman
Robinson gives about 57.4 kg and the healthy range spans roughly 50.4–67.8 kg. The spread shows why a single “ideal” number is less useful than a band.
Comparing with your BMI
Find a formula figure you like, then check it in the BMI calculator — anything landing in the 18.5–24.9 band is a reasonable, healthy weight for your height.
Frequently asked questions
Is there really an “ideal” weight?
Not a single one. Health is compatible with a range of weights, which is why this tool leads with a range rather than one number. The named formulas each give a point estimate, but they’re approximations, not personalised goals.
Why do the four formulas give different answers?
They were derived at different times from different populations, so their base weights and per-inch increments differ. Hamwi tends highest and Robinson lowest for the same person. Seeing them side by side is more honest than trusting any one.
What were these formulas originally for?
Mostly for estimating drug dosages from height, not for setting weight goals. That heritage is why they ignore muscle, body fat and frame — factors that matter a lot for an individual’s healthy weight.
Do they account for muscle or body composition?
No. Like BMI, they use only height and sex, so a muscular person may weigh more than the formulas suggest while being perfectly healthy. Use the body fat calculator for a composition-aware estimate.
Which number should I use?
Treat the BMI-based range as the practical answer and the formulas as reference points within or near it. If you want a specific target, discuss it with a doctor or dietitian who can factor in your build and health.
Does it work for very short or very tall people?
The formulas are least reliable at the extremes, since they extrapolate from a 5-foot base. The tool still computes a value, but take results with extra caution outside the typical adult height range.
Is this suitable for children?
No. These are adult formulas. Healthy weight for children and teens is assessed with age- and sex-specific growth charts by a paediatrician, not with these equations.
Are my details kept private?
Yes. Everything is computed in your browser; nothing is uploaded and analytics never receives your height or sex.
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