Ideal Weight Calculator
Healthy weight range for your height from several formulas.
Used to pick the formula coefficients.
Average ideal weight
- Healthy estimate range
- 70.4 kg – 75.2 kg
- Devine
- 73.2 kg
- Robinson
- 71.2 kg
- Miller
- 70.4 kg
- Hamwi
- 75.2 kg
An estimate, not a target or a diagnosis. These formulas use only height and sex, so they ignore frame size, age, and muscle mass. Discuss a healthy weight for you with a clinician.
How the ideal weight calculator works
“Ideal body weight” is a historical clinical term, not a determination of a person’s healthiest weight. This tool compares four older height-and-sex formulas that have been used in dosing or reference contexts, then reports their mathematical average and spread. The average is not a validated fifth formula.
All four share the same shape. Each defines a base weight at a height of 5 ft (60 inches) and adds a fixed number of kilograms for every inch above that:
ideal weight = base + per-inch increment x inches over 5 ft
where inches over 5 ft = max(0, height in inches - 60). Heights at or below 5 ft contribute no increment, so the result is simply the base weight for that sex.
The coefficients, by formula and sex:
| Formula | Male | Female |
|---|---|---|
| Devine (1974) | 50.0 + 2.3 per in | 45.5 + 2.3 per in |
| Robinson (1983) | 52.0 + 1.9 per in | 49.0 + 1.7 per in |
| Miller (1983) | 56.2 + 1.41 per in | 53.1 + 1.36 per in |
| Hamwi (1964) | 48.0 + 2.7 per in | 45.5 + 2.2 per in |
The calculator works internally in centimetres and kilograms, then converts to pounds and inches for display if you choose imperial units. The average is the mean of the four estimates, and the range shows the lowest and highest of them, so you can see how much the formulas disagree.
Worked example
Take a male who is 178 cm tall, which is 5 ft 10.08 in. The height over 5 ft is 178 / 2.54 - 60 = 10.08 inches.
- Devine:
50 + 2.3 x 10.08 = 73.18 kg - Robinson:
52 + 1.9 x 10.08 = 71.15 kg - Miller:
56.2 + 1.41 x 10.08 = 70.41 kg - Hamwi:
48 + 2.7 x 10.08 = 75.21 kg
The four estimates average to 72.49 kg, and they spread from 70.41 kg to 75.21 kg. That five-kilogram gap is normal: it reflects genuine disagreement between the formulas, not an error, and it is why a single headline number would be misleading.
How to use it
- Choose metric (cm, kg) or imperial (in, lb) units. The math is identical; only the input and output units change.
- Select male or female to pick the coefficient set.
- Enter your height. The tool updates the four estimates, their average, and the range as you type.
- Read the output as a comparison of historical formulas. Do not select a dosing weight without using the instructions for the specific medication or clinical protocol.
Limitations
This is a historical formula comparison, not medical advice, a personal weight goal, or a dosing tool. The formulas use only height and a binary sex category and are unreliable at some heights and for many body types and clinical populations. Medication dosing may require actual, lean, adjusted, predicted, or another defined body weight depending on the drug. Follow the specific clinical protocol and a qualified professional rather than this output.
Sources and scope
- Jurisdiction
- Historical adult ideal-body-weight formulas
- Data current to
- Formula comparison; not a current clinical target
- Last updated
- Ideal body weight: a commentary — Journal of the American College of Emergency Physicians Open via PubMed Central
Frequently asked questions
Why do the four formulas give different numbers?
The formulas have different and sometimes poorly documented origins. Published reviews note that some were derived from older weight-for-height tables while others, including Hamwi, lack a reported development method. Their disagreement is a limitation, not evidence that averaging them creates a correct personal weight.
What counts as height over 5 feet?
Every formula starts from a base weight at 5 ft (60 inches) and adds a fixed amount for each inch above that. The tool converts your height to inches, subtracts 60, and multiplies the remainder by the formula's per-inch figure. The fractional part of an inch counts, so 5 ft 10.1 in adds slightly more than 5 ft 10 in.
What happens if I am shorter than 5 feet?
These formulas were only validated for heights above 5 ft, so below that the per-inch increment is clamped to zero and you simply see the base weight for your sex. Treat any result near or below 5 ft as a rough floor rather than a precise estimate, and ask a clinician.
Is ideal body weight the same as a healthy weight?
No. Ideal body weight is a clinical shorthand built from height and sex alone. It was designed for medication dosing, not as a personal goal, and it ignores frame size, age, body composition, and muscle mass. A muscular athlete can sit well above their ideal body weight and still be perfectly healthy. Use it as context, not a target.
Why ask for sex instead of gender?
The coefficients were derived from studies that recorded biological sex, and male and female bodies carry weight differently at the same height. The tool uses the value only to pick which set of numbers to apply; nothing you enter is stored or sent anywhere.