Free Ideal Weight Calculator
Compare the Devine, Robinson, Miller and Hamwi ideal body weight formulas with your healthy BMI range.
Enter your sex and height. The calculator applies four published ideal body weight formulas (Devine, Robinson, Miller and Hamwi), shows each result and their average, and compares them with the weight range for a healthy BMI of 18.5 to 24.9.
How to use the Ideal Weight Calculator
- Choose metric or US units and enter your own measurements.
- Read the result and the supporting numbers shown beneath it.
- Use the explanation below to see what the number means, and talk to a doctor about anything that worries you.
About the Ideal Weight Calculator
Compare the Devine, Robinson, Miller and Hamwi ideal body weight formulas with your healthy BMI range.
Health numbers are easier to understand when you can see how they are worked out. These calculators use published formulas and explain what the result does and does not tell you. They give general estimates and are not medical advice.
What 'ideal weight' means
Ideal body weight formulas estimate a reference weight from your height and sex. They are old, simple equations, and several were written to help doctors calculate medicine doses rather than to set personal goals. They are still widely quoted, so this tool shows all four side by side.
The four formulas
Each formula starts with a base weight for 5 feet (60 inches) of height and adds a set amount for every inch above that. The results below are in kilograms.
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 + 2.3 per inch | 45.5 + 2.3 per inch |
| Robinson (1983) | 52 + 1.9 per inch | 49 + 1.7 per inch |
| Miller (1983) | 56.2 + 1.41 per inch | 53.1 + 1.36 per inch |
| Hamwi (1964) | 48 + 2.7 per inch | 45.5 + 2.2 per inch |
Worked example
A man who is 5 ft 9 in (69 in, about 175 cm) is 9 inches over 5 feet. The Devine formula gives 50 + 2.3 × 9 = 70.7 kg (about 156 lb). Robinson gives 52 + 1.9 × 9 = 69.1 kg, Miller gives 56.2 + 1.41 × 9 = 68.9 kg, and Hamwi gives 48 + 2.7 × 9 = 72.3 kg. The four land within about 3.5 kg of each other.
A better guide: the healthy BMI range
The calculator also shows the weights that give a BMI between 18.5 and 24.9 at your height. For a person 175 cm tall that is roughly 57 to 76 kg (125 to 168 lb), a much wider and more realistic span than a single number.
What the formulas leave out
They do not consider age, frame size, muscle mass or health conditions. A strength athlete, a person with a large frame and an older adult can all be healthy well outside the formula results. They also assume adult height, so they are not for children.
- Use the result for a rough reference only.
- If weight is a concern, ask a doctor to look at waist size, blood tests and blood pressure as well.
- For a view of body composition, try the body fat calculator.
Getting started with the Ideal Weight Calculator
Using the ideal weight calculator takes a minute or two. Your entries are saved in this browser, so you can come back later and carry on.
Tips for better results
Think of the answer as a range, not a target. The formulas ignore age, build and muscle, so the healthy BMI range at the bottom of the results is usually the more useful guide.
Use measurements you have taken recently, not remembered ones.
These tools give general estimates and are not medical advice. Check anything important with a doctor or registered dietitian.
Privacy and where your data goes
Everything you type into the ideal weight calculator stays on your own device. Zapxa does not receive your numbers or documents. If you clear your browser data, your saved entries will be removed, so download a PDF of anything you want to keep.
Frequently asked questions
What is my ideal body weight?
There is no single right answer. The four formulas usually agree within a few kilograms, and the healthy BMI range for your height is wider still. The best weight for you is one you can maintain while feeling well.
Which ideal weight formula is best?
None is best. They were written for different purposes, for example the Devine formula was created for drug dosing. Looking at the spread between them is more useful than picking one.
Do the formulas work for short people?
They start at 5 feet (152 cm). Below that they all return the base weight, so use the BMI range instead.
Does ideal weight depend on age or muscle?
The formulas ignore both. An athlete, an older adult and a person with a large frame can all be healthy well away from the formula result.
Related Health & Age tools
- BMI Calculator — Work out your body mass index, see your adult weight category and the healthy weight range for your height.
- BMR Calculator — Estimate the calories your body burns at rest each day with the Mifflin-St Jeor and Harris-Benedict formulas.
- Calorie Calculator — Estimate daily calories to maintain, lose or gain weight from your age, size and activity level.
- Body Fat Calculator — Estimate body fat percentage from neck, waist and hip measurements using the U.S. Navy method.
- Pregnancy Due Date Calculator — Estimate a due date from the first day of your last period, with trimester dates and weeks pregnant.