An ideal weight for a man is calculated by plugging his height and sex into one of four classic formulas — Devine, Robinson, Miller, or Hamwi — each of which gives a slightly different target weight. Every formula works the same way: a base weight for a man exactly 5 feet (152 cm) tall, plus a fixed amount added for every inch of height above that. The Devine formula (1974), built by Dr. B.J. Devine to estimate medication doses, uses 50 kg plus 2.3 kg per inch over 5 feet and has become the most cited ideal body weight equation in clinical medicine. Hamwi (1964) uses 48 kg plus 2.7 kg per inch and was designed by Dr. G.J. Hamwi to estimate nutrition needs, which is why it tends to land highest. Robinson (1983) and Miller (1983), both reworked from Devine's original against newer data, generally sit lower: 52 kg plus 1.9 kg per inch for Robinson and 56.2 kg plus 1.41 kg per inch for Miller. Because each formula has a different starting point and slope, the spread between the four numbers widens as height climbs. The Ideal Weight Calculator reports all four side by side, their average, and a healthy BMI range, each shown in both kilograms and pounds.
The Four Formulas, Side by Side
Here is a closer look at the four formulas this calculator uses for men. Each is a different researcher's estimate, fitted to different data, so the numbers diverge by design.
| Formula | Year | Base weight at 5 ft (152 cm) | Added per inch above 5 ft | Original use |
|---|---|---|---|---|
| Devine | 1974 | 50 kg | 2.3 kg | Medication dosing — most cited in medicine |
| Robinson | 1983 | 52 kg | 1.9 kg | Reworked Devine against fresh data |
| Miller | 1983 | 56.2 kg | 1.41 kg | Reworked Devine — generally lowest result |
| Hamwi | 1964 | 48 kg | 2.7 kg | Nutrition planning — generally highest result |
Reading the table row by row, the same pattern shows up for men across all four: a heavier 5-foot baseline, with a different growth rate per inch. Devine and Hamwi add more weight per inch (2.3 and 2.7 kg respectively), while Robinson and Miller grow more slowly. The result is that for a man around 5'9" (175 cm), the spread between the lowest and highest formula is roughly 3 to 4 kg — a small but real difference for someone deciding whether their current weight is "on target."
It is worth noting why the numbers disagree. There is no single biologically defined "ideal" weight; each formula is a line of best fit through different patient data collected decades ago. Devine came from adult patients in a hospital, Robinson and Miller reworked those numbers with newer samples, and Hamwi started from nutrition intake tables. None of them has ever been re-derived against modern body-composition data, which is part of why the healthy BMI range is now generally preferred as the population-level benchmark.
How to Calculate Ideal Weight for Men Step by Step
- Open the Ideal Weight Calculator and pick your sex — the male selection routes the calculation through the four male formulas above.
- Choose a height unit. The tool accepts centimeters, inches alone, or feet plus inches. Pick whichever you measure in most easily.
- Type your height. If you chose feet-plus-inches, fill in both the feet box and the inches box — leaving the inches box blank will give an incomplete input.
- Read your result instantly. There is no button to press and nothing is uploaded, so the four formula values, their average, and the healthy BMI range appear the moment you finish typing.
- Every number — each formula, the average, and both ends of the BMI range — is shown in both units, so you can read whichever is familiar.
- Compare the four formulas to the BMI band. The BMI range (typically 18.5 to 25, the WHO normal band) is usually the most informative single figure, because it is grounded in population health data rather than a mid-20th-century rule of thumb.
For someone who already knows their height in centimeters and wants a quick sanity check, the metric input is the fastest path: pick cm, type the number, and the four formula values, average, and BMI band all update in the same step.
Why Men's Ideal Weight Numbers Spread Further at Taller Heights
The difference between formulas is not a fixed number of kilograms — it scales with height. A 5'4" man will see all four formula answers bunch within a couple of kilograms of each other, while a 6'2" man will see them spread by about 10 kg.
The reason is the slope. Hamwi adds 2.7 kg per inch and Devine adds 2.3 kg, while Miller adds only 1.41 kg. For each inch above 5 feet, the gap between Hamwi and Miller widens by about 1.3 kg. Multiply that by the number of inches above 5 feet, and a tall man is reading a band of formula answers rather than a single number. This is one reason why a tall man can weigh what looks like a wide range of "ideals" depending on which formula he trusts.
The healthy BMI range sidesteps this problem. It is anchored to a band, not a point, so it scales naturally with height without depending on which researcher you pick. The numbers come from a different source entirely — the standard body mass index equation (weight in kg divided by height in metres squared), with the WHO normal band of 18.5 to 25 applied to your height. Multiplying each end of that band by your height in metres squared converts it into an actual weight range. For example, at 175 cm (1.75 m), the lower bound is 18.5 × 1.75² ≈ 56.7 kg and the upper bound is 25 × 1.75² ≈ 76.6 kg, giving a healthy range of about 57 to 77 kg rather than a single target.
Limits to Keep in Mind for Men
These formulas were calibrated for adults of 5 feet and taller, and they have a hard floor: below 5 feet, the formulas collapse to their baseline value and stop being meaningful. The tool flags this and points you to the BMI range instead, which still works at shorter heights.
They also assume a binary male or female input and do not apply to children. There is no built-in adjustment for age, ethnicity, or medical history. A muscular athlete can sit well above every formula's "ideal" and still be perfectly healthy — the formulas cannot see muscle, bone density, or frame size. The reverse is also true: a small-framed man with very low muscle mass can land inside the formula range while still carrying more body fat than the numbers suggest.
Treat the result as a rough, informational estimate, not a diagnosis or a target set by a professional. For guidance on a healthy weight specifically for you, a doctor or registered dietitian can take muscle mass, frame size, and medical history into account in ways the formulas cannot.
Putting the Numbers Together
The most useful way to read an ideal body weight for a man is as a band, not a single number. A practical reading order is:
- Start with the BMI range. For an adult man at a typical height, the WHO band of 18.5 to 25 is the most defensible single figure because it comes from population health data, not a 1960s or 1980s rule of thumb.
- Cross-check with the four-formula average. If your current weight sits inside both the BMI band and the average of Devine, Robinson, Miller, and Hamwi, you are reading in a sensible place.
- Note the formula spread. A tall man should expect a wider spread between formulas than a shorter man — that is a property of the formulas, not a sign that something is wrong.
- Adjust for what the formulas cannot see. Frame size, muscle mass, and athletic build will move the "right" number up or down by several kilograms without changing your actual health status.
For a deeper look at how the BMI band is computed, the BMI Calculator breaks the same range down by category. If you want to translate a target weight into something you can wear, a clothing size converter gives a second anchor for what a healthy weight actually looks like on your frame.
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