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 clinical estimate of a reasonable weight for a given height, originally built so that medications could be dosed by body size. This tool reports four classic formulas side by side, then summarises them with an average and a range.
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 range as the headline, not any single formula. If you need one number for a clinical dosing reference, Devine is the conventional choice.
Limitations
This is an estimate, not medical advice and not a personal goal. Ideal body weight depends only on height and sex, so it cannot account for frame size, age, sex differences in body composition, or muscle mass. It was built for medication dosing and population reference, not for setting an individual target weight. A more complete picture combines several measures, such as body mass index, waist circumference, and body fat, interpreted alongside your health history. Treat the numbers here as context for a conversation with a clinician, who can advise on a weight that is healthy for you.
Frequently asked questions
Why do the four formulas give different numbers?
Each was published in a different decade from a different population, so the starting weight at 5 ft and the amount added per inch above 5 ft differ. Devine came first, in 1974, and is still the one most drug-dosing tables use. Robinson, Miller, and Hamwi adjusted the coefficients to fit their own data. None is the single correct answer, which is exactly why this tool shows all four plus their average and spread rather than a false precision.
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.