Ideal Weight Calculator
Calculate ideal weight range
Ideal Weight Calculator tool
Ideal Weight Calculator
Ideal Weight Calculator: key facts
- What it does
- Calculate ideal weight range
- Category
- Health & Fitness Calculators
- Cost
- Free, with no account, sign-up, or install.
- Your data
- Runs entirely in your browser — the files and text you enter are never uploaded to a server.
- Last reviewed
- . Report an incorrect result.
About the Ideal Weight Calculator
There is no single "ideal weight", which is exactly why this calculator shows four. It runs your height and sex through the Devine, Robinson, Miller, and Hamwi formulas — the classic clinical estimates — and reports each result alongside their average, so you get a sensible range rather than one arbitrary figure.
These formulas were developed for medical contexts like dosing and are widely used as healthy-weight references. Seeing all four together is the value here: they disagree slightly, and the spread between them is a more honest picture than any one number. Anyone setting a weight goal can use the range as a grounded target rather than chasing a single point.
How to use it
- Select your sex.
- Enter your height in centimeters.
- Read the estimated average ideal weight.
- Compare the individual Devine, Robinson, Miller, and Hamwi results to see the range they suggest.
Four formulas, and their average
There is no single accepted equation for ideal body weight, so this tool runs four of the best-known and reports each alongside their mean. All four share the same structure: a base weight for a height of five feet, plus a fixed increment for every inch above that. Your height in centimetres is converted to inches internally to feed them.
They disagree, and the disagreement is the useful part. Hamwi, published in 1964, is the most generous; Miller tends to sit lowest; Devine and Robinson fall between. Seeing a spread of several kilograms across four respected formulas is a more honest answer than a single confident number would be.
Devine's equation in particular was never designed for this purpose. It was published in 1974 as a way of scaling drug doses to body size, and it drifted into use as a body-weight target afterwards — which is worth knowing before treating its output as a health goal.
- At the default 175 cm, male: Devine gives 70.46 kg, Robinson 68.91, Miller 68.75, and Hamwi 72.02 — averaging 70.03 kg.
- That is a spread of 3.27 kg between the highest and lowest formula for one person at one height.
- Because every equation is linear in inches above five feet, each additional centimetre of height adds between roughly 0.5 and 1.1 kg depending on which one you read.
Why use this version
- It computes four established formulas at once and averages them, giving a defensible range instead of a single, falsely precise number.
- Showing each named formula's result lets you see how much the methods differ for your height.
- It needs only height and sex, the inputs these formulas actually use, so it is quick and unambiguous.
- Everything is calculated locally, so your figures never leave your device.
Why no formula can give you a target
Every one of these equations takes only height and sex as inputs. Frame size, muscle mass, bone density, age, and body composition are all absent, which means a heavily built person and a slightly built person of identical height receive identical answers. A muscular athlete will frequently sit well above every figure here while being in excellent health.
They were also developed decades ago on populations that were not globally representative, and clinical practice has largely moved on. Where a number is needed today, a healthy BMI range, a waist measurement, or a body composition estimate are all more informative than an ideal weight figure — and each of those describes a range rather than a single point.
Treat the output as historical context and a rough orientation, not a goal. If you are trying to decide what weight is right for your body, that is a question for a doctor or dietitian who can see your build, your history, and your health markers — none of which a height-only formula can know.
Frequently Asked Questions
Why are there four different ideal weight formulas?
The Devine, Robinson, Miller, and Hamwi formulas were developed at different times for clinical use and each weights height slightly differently. None is definitively "correct," so this calculator shows all four and their average to give you a realistic range.
Is ideal weight the same as a healthy weight?
Not exactly. These formulas estimate a reference weight based only on height and sex; they do not account for muscle mass, frame size, or body composition. Treat the result as a guideline alongside measures like BMI and body fat percentage.
Why doesn't it ask for my current weight?
The formulas estimate a target weight from height and sex alone — your current weight is not an input. Compare the result to your actual weight yourself to see how far above or below the estimated range you are.
Do frame size and muscle affect the result?
The formulas ignore both, using only height and sex. A muscular or large-framed person may sit healthily above the estimate, while a small-framed person may sit below it — another reason to read the four-formula range alongside body composition rather than treating one number as a goal.
