About the Ideal Weight Calculator
An ideal weight calculator gives a reference weight for your height using established clinical formulas. These formulas originated in medicine for drug dosing rather than as aesthetic or fitness targets, and they are best understood as a rough midpoint rather than a goal.
The formula
Devine: men 50 + 2.3·(inches over 5 ft); women 45.5 + 2.3·(inches over 5 ft)Height above five feet is measured in inches. The Robinson, Miller, and Hamwi formulas follow the same structure with slightly different constants, which is why published ideal weights vary.
How to use this calculator
- 1Enter your Height (cm). The field starts at
175, which you can overwrite. - 2Enter your Gender (1=Male, 2=Female). The field starts at
1, which you can overwrite. - 3Read the result straight away — it recalculates as you type, so there is no button to press. Use Share to copy a link that reopens the page with your exact numbers filled in.
Worked example
| Input | Value |
|---|---|
| Height (cm) | 175 |
| Gender (1=Male, 2=Female) | 1 |
Result
Ideal Weight:
68.9 kg (151.9 lbs)
Those are the values the page loads with, so you can reproduce this result yourself and then change one field at a time to see what drives the outcome.
Understanding your result
The Devine formula was published in 1974 to standardise drug dosing, not to define a healthy physique. That origin explains its narrowness: it uses only height and sex, ignoring frame size, muscle mass, age, and body composition entirely. A muscular person will exceed it while being demonstrably healthy.
A healthy weight is a range, not a point. The normal BMI band from 18.5 to 24.9 typically spans 20 kilograms or more for a given height, and where you sit within it depends on frame and composition. Treating a single formula output as a target sets an arbitrarily precise goal on a genuinely broad question.
Things worth knowing
- The BMI range for your height gives a more realistic healthy band than any single ideal weight figure.
- These formulas take no account of frame size. Wrist circumference and shoulder width shift the sensible range materially.
- Athletes routinely exceed ideal weight formulas because muscle is dense. That is not a health problem.
- The formulas were designed for adults and are not appropriate for children or adolescents.
- Body composition and fitness predict health outcomes far better than proximity to a formula weight.
Frequently asked questions
How is ideal body weight calculated?+
Most formulas start from a base weight at five feet tall and add a fixed amount per additional inch — 2.3 kg in the Devine formula. Different formulas use slightly different constants, which is why results vary.
Are these formulas actually useful?+
For their original purpose, drug dosing, yes. As a personal weight target they are crude, because they ignore frame size, muscle mass, age, and body composition entirely.
What is a better way to set a weight goal?+
Use the BMI range for your height as a band rather than a point, and track body composition and fitness markers alongside weight. A 20 kg range is normal for any given height.
Why do different calculators give different ideal weights?+
Because Devine, Robinson, Miller, and Hamwi all use different constants derived from different populations. The spread between them is itself a reminder that no single number is authoritative.