Ideal Weight Calculator
Hamwi, Devine, Robinson and Miller formulas, plus the BMI 18.5 to 24.9 range
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
Units
Sex
These hospital dosing formulas were built for average frames. Muscle, bone and ethnicity shift a healthy weight. BMI itself is a screening tool, not a verdict.
Estimates only. Not medical advice and not a diagnosis. Talk to a clinician about your own numbers.
About this tool
Ideal body weight formulas (Hamwi, Devine, Robinson, Miller) were built for drug dosing and average frames, not for judging athletes. The BMI 18.5 to 24.9 band at your height is shown beside them. Muscle, bone and ethnicity move a healthy weight. South Asian screening often uses a lower BMI cut-off than 25. Treat the cluster as a range, not a single correct kilogram. Estimates only. Not medical advice.
How to use this tool
- Choose metric or imperial and sexThe classic formulas are sex-specific. Height is the only measurement they need.
- Enter heightThe BMI range uses height squared, so measure it carefully.
- Compare formulas to the BMI bandDevine is widely cited in hospitals. The BMI band is often the more honest public range.
How ideal weight formulas work
Each formula starts from a base weight at 5 ft (152.4 cm) and adds a fixed amount for every inch above it. Devine uses 50 kg for men and 45.5 kg for women plus 2.3 kg per inch; Robinson 52 / 49 kg plus 1.9 / 1.7 kg; Miller 56.2 / 53.1 kg plus 1.41 / 1.36 kg; Hamwi 48 / 45.5 kg plus 2.7 / 2.2 kg. For a man 5 ft 10 in tall that gives about 73, 71, 70 and 75 kg.
The spread is the point: there is no single ideal weight. The healthy BMI range at the same height - 18.5 to 24.9, or about 58 to 79 kg at 5 ft 10 in - is a wider and more useful target than any one formula.
Key features
- Four named formulas plus the healthy BMI weight band.
- Metric kilograms or imperial pounds.
- Context that these numbers were dosing tools, not a verdict on your body.
- Private in your browser.
Common uses
- A height-to-weight range for a health form that asks for "ideal weight".
- Comparing a BMI result with older hospital formulas.
- A starting conversation with a clinician, not a self-diagnosis.
Tips for better results
- If you lift, ignore a "high" BMI and look at waist, performance and how you feel.
- Use the BMI calculator if you already know both height and weight.
- Frame size (wrist) is not in these formulas. They assume an average build.
Mistakes to avoid
- Picking the lowest formula and calling it a goal weight.
- Applying adult formulas to children.
- Using one number as a diagnosis of underweight or obesity.
Frequently asked questions
There is no single best number. Devine is widely cited in hospitals. The BMI 18.5 to 24.9 band is often the more honest range for the public.
BMI cannot tell muscle from fat. Use waist, performance and a clinician, not only the scale.
The classic inch-based equations were built around average adult heights. Very short or very tall people should lean on the BMI band and clinical advice.
Each was fitted to different data for a different purpose - Devine for drug dosing in 1974, Robinson and Miller as later refinements, Hamwi as a quick clinical rule. Their spread is a reminder that no single kilogram is correct for everyone your height.
Yes. People with a larger bone structure carry more weight at a healthy body fat level. A rough check is wrist size: if your thumb and middle finger overlap around your wrist you likely have a small frame; if they do not meet, a large one.
Use the range as context, not a target to hit exactly. Waist size, fitness, blood pressure and how you feel say more about health than how close you are to a formula's number.