Calculators
Ideal Body Weight Calculator
Calculate ideal body weight from height and sex with the Devine, Robinson, Miller and Hamwi formulas, plus the healthy BMI range.
- Runs in your browser
- Nothing uploaded
The tool
Enter your numbers below. Results update as you type, and nothing leaves your browser.
Everything you enter stays on your own machine. Nothing is sent to us or to anyone else, which you can confirm in your browser network tab.
What people use it for
- Setting a reference weight
- Comparing estimation formulas
- Health education
- Fitness goal setting
About this tool
What the Ideal Body Weight Calculator does
Ideal body weight (IBW) formulas estimate a reference weight from height and sex. They were developed for clinical uses and differ slightly from each other, so this calculator shows several alongside the weight range that corresponds to a healthy BMI.
Formula
- Devine: 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 feet
- Robinson, Miller and Hamwi use different constants per inch
- Healthy BMI range = 18.5 to 24.9 × height (m)²
Worked example
Using the starting values in the calculator above:
| Input | Value |
|---|---|
| Sex | Male |
| Height | 175 cm |
| Result | Value |
|---|---|
| Devine | 70.5 |
| Robinson | 68.9 |
| Miller | 68.7 |
| Hamwi | 72.0 |
| Healthy BMI weight range | 56.7 to 76.3 kg |
How to read the result
These formulas do not account for frame size or muscle mass; treat them as reference points, not targets.
For people under 5 feet tall the formulas are less reliable.
General information, not medical advice. Speak to a qualified health professional before making changes to diet, exercise or treatment.
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Questions
Questions about this tool
The things clients actually want to know — costs, timelines, ownership and what happens after launch.
A reference weight estimated from height and sex, originally developed for clinical calculations.
None is perfect; Devine is the most widely used. Comparing several gives a sensible range.
Not exactly; a healthy weight range based on BMI is usually wider.
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