A range, not a verdict
The headline result is the full healthy weight range for your height, because there is no single correct weight for a given height. The visual band shows how wide that range actually is.
Free health reference tool
Ideal Weight Calculator — Healthy Weight Range by Height
See the healthy weight range for your height alongside four classic clinical estimates — Devine, Robinson, Miller and Hamwi — with frame-size adjustment, metric and imperial units, and a plain explanation of what each number does and does not mean.
- Four formulas compared side by side
- Healthy BMI range, not a single target
- Nothing you enter is uploaded
Sex at birth
The classic formulas were published with separate male and female constants.
cm
Height
ft
in
kg
Only used to place a marker on the range. Leave it blank if you prefer.
yrs
Body frame
Hamwi adjusts by 10% for frame size. Measure your wrist to check which you are.
Result
Healthy weight range for your height
56.7 – 76.3 kg
125 – 168 lb · based on a BMI of 18.5 to 24.9
Where your weight sits
Add your current weight to see the marker.The green band is the weight range that corresponds to a BMI of 18.5 to 24.9 at your height.
Average of four formulas
—
Midpoint of healthy range
—
Your BMI
—
Enter a current weight
Range width
—
Healthy weights vary this much at one height
| Formula | Year | Result | Also |
|---|
These formulas were designed in the 1960s to 1980s for medication dosing and actuarial tables, not as personal goals. They ignore muscle mass, bone density, body composition, ethnicity and health history, and they disagree with each other by several kilograms at the same height. Treat the healthy range as the meaningful output and the single numbers as historical reference points. For advice about your own weight, speak to a doctor or a registered dietitian.
Why this ideal weight calculator is different
Most pages give you one number and imply it is a target. A range, four formulas and an honest explanation of their limits is more useful and more accurate.
Four formulas, shown together
Devine, Robinson, Miller and Hamwi all disagree. Seeing them side by side makes the spread obvious instead of hiding it behind one confident-looking figure.
Frame size accounted for
Hamwi adds or subtracts 10% for small and large frames. Most calculators skip this entirely, which is why their numbers feel wrong for broad or slight builds.
Both unit systems, always
Every result is shown in kilograms and pounds at the same time, so you never have to convert or switch tabs to compare with a chart you were given elsewhere.
Honest about the limits
Age-appropriate handling for under-18s, a clear note on what these formulas were built for, and no pretence that a 1974 dosing equation knows your body composition.
Completely private
Height, weight and age never leave your device. The calculation runs in your browser, nothing is stored, and there is no account to create.
How to use the calculator
Four inputs, and only two of them are required.
Choose your units
Switch between centimetres and kilograms or feet, inches and pounds. Results always appear in both regardless of what you pick.
Enter height and sex
These two drive every formula. Height is by far the strongest input, which is why the same weight range applies to very different bodies.
Add frame size if you know it
Wrap your thumb and middle finger around the opposite wrist. Overlapping suggests a small frame, just touching medium, not meeting large.
Read the range first
Look at the green band before the individual numbers. If your current weight sits inside it, the individual formulas are not telling you anything useful.
What people use this for
Ideal body weight equations still have real, specific jobs outside of personal goal setting.
Clinical dosing reference
Devine and Robinson are still used to calculate drug doses and ventilator tidal volumes from height.
Understanding a BMI result
Seeing BMI translated back into a weight range in kilograms makes the number far easier to interpret.
Sizing sports categories
Rowing, martial arts and weight-class sports reference height-to-weight tables when placing athletes.
Preparing for a check-up
Arriving with your own numbers makes the conversation with a clinician quicker and more specific.
Curiosity, settled quickly
If two charts disagree, this shows you why: they are using different equations from different decades.
Nutrition study notes
Students comparing IBW equations can read all four constants and results in one place.
How ideal body weight is actually calculated
Every classic ideal body weight formula follows the same shape: a base weight for a person five feet tall, plus a fixed amount for each additional inch of height. They differ only in those two constants, and they were each fitted to a different population for a different purpose. That is why four respected equations can produce answers that differ by five kilograms or more for the same person.
The four formulas
- Hamwi (1964) — men 48.0 kg + 2.7 kg per inch over 5 ft; women 45.5 kg + 2.2 kg per inch. Adjust by 10% for small or large frames.
- Devine (1974) — men 50.0 kg + 2.3 kg per inch; women 45.5 kg + 2.3 kg per inch. Built for calculating drug doses, and still the clinical default.
- Robinson (1983) — men 52.0 kg + 1.9 kg per inch; women 49.0 kg + 1.7 kg per inch. A modest revision of Devine.
- Miller (1983) — men 56.2 kg + 1.41 kg per inch; women 53.1 kg + 1.36 kg per inch. Produces the flattest curve of the four.
The healthy BMI range method
The more current approach skips the fixed constants entirely. Multiply the square of your height in metres by 18.5 and by 24.9, and you get the weight range the World Health Organization classifies as healthy for adults. At 175 cm that is roughly 56.7 kg to 76.3 kg. Because it is a range rather than a point, it acknowledges what the older equations do not: two healthy adults of the same height can legitimately differ by twenty kilograms.
What these numbers cannot tell you
- They do not measure body composition. A muscular athlete routinely reads as overweight on BMI.
- They were derived largely from white North American and European populations, and fit less well elsewhere.
- They do not apply to children or teenagers, who are assessed against age-and-sex percentile growth charts instead.
- They ignore pregnancy, amputation, oedema, and most medical conditions that affect weight.
- They say nothing at all about health behaviours, fitness, blood pressure or metabolic markers.
If you want to explore the surrounding numbers, our BMI calculator includes a waist-to-height ratio, the body fat calculator uses the US Navy circumference method, and the macro calculator covers daily energy and macronutrient reference values.
Ideal weight FAQ
The questions people ask most about height-to-weight numbers.
What is my ideal weight for my height?
There is no single ideal weight for a height. The most useful answer is a range: the weights that correspond to a BMI of 18.5 to 24.9 at your height. Enter your height above and the calculator shows that range in both kilograms and pounds, along with what four older clinical formulas would each estimate.
Which ideal weight formula is most accurate?
None of them is accurate in the way people expect, because they only use height and sex. Devine is the most widely used in clinical settings, mostly because drug dosing conventions were built around it rather than because it predicts health outcomes better. For general purposes the healthy BMI range is a more defensible answer than any single formula.
Why do the four formulas give different answers?
Each was fitted to a different dataset for a different purpose between 1964 and 1983, so their base weights and per-inch increments differ. Miller produces a flatter curve than Hamwi, for example, so the gap between them widens the taller you are. The spread is genuine information: it shows how imprecise the whole concept is.
How do I know my body frame size?
Wrap your thumb and middle finger around the opposite wrist. If they overlap, that suggests a small frame; if they just touch, medium; if they do not meet, large. It is a rough proxy for skeletal width, and only the Hamwi formula in this calculator adjusts for it, by 10% in each direction.
Does this work for children and teenagers?
No. These formulas are validated for adults only. Children and adolescents are assessed with age-and-sex-specific percentile growth charts, because normal weight changes constantly through development. If you enter an age under 18 the calculator tells you this rather than showing an adult result.
Why does a muscular person read as overweight?
Because neither BMI nor the IBW formulas can distinguish muscle from fat. Muscle is denser, so a well-trained athlete at a healthy body fat percentage frequently lands above the range. This is a known limitation, not an error, and it is one reason clinicians pair BMI with waist measurement or body composition testing.
Does age change ideal weight?
The formulas themselves do not use age for adults, and the healthy BMI range is the same at 25 as at 65. Body composition does shift with age, and some research suggests a slightly higher BMI is not harmful in older adults, but no widely adopted equation encodes that. Age is collected here only to flag when the adult formulas should not be used.
Is my data saved anywhere?
No. Every calculation happens in your browser using JavaScript. Your height, weight and age are never transmitted or stored, and the page keeps working if you go offline after it loads.
A range is a better answer than a number
Check your healthy weight range and see how four classic formulas compare, with the context that explains why they disagree. Free, instant and entirely private.
General information only, not medical advice. Nothing you enter is uploaded, stored or shared.