Find an ideal body weight range for men, based on height.
The Devine formula, originally developed for medication dosing, widely repurposed as a general ideal-weight reference.
Men: 50kg + 2.3kg per inch over 5 feet
The ideal weight calculator for men gives a reference body weight from height alone, using the Devine formula: 50 kg for a man 5 feet tall, plus 2.3 kg for every inch above that.
Men look this up when they want a quick number to aim for, when a doctor or trainer mentions 'ideal body weight', or when comparing their current weight with a textbook reference. In hospitals the same figure, often written IBW, is used to calculate doses of some medicines and ventilator settings, which is where the formula began.
The answer is a single reference figure, not a strict goal. Two men of the same height can be healthy at quite different weights depending on frame size and muscle.
1. Measure height in centimetres without shoes.
2. Convert to inches by dividing by 2.54.
3. Subtract 60 inches (5 feet) to get inches over 5 feet. If the result is negative, use 0.
4. Multiply the inches over 5 feet by 2.3 kg.
5. Add the men's base weight: ideal weight = 50 + 2.3 × (height in inches − 60).
6. Optionally compare the result with the weight range that gives a BMI of 18.5 to 24.9 at your height.
Dr B. J. Devine published the formula in 1974 in a note about dosing the antibiotic gentamicin, which must be based on lean body size rather than total weight. It was not derived from a study of health outcomes. Its simplicity made it spread into nutrition textbooks and calculators as an 'ideal weight'. Other formulas from the same era follow the same pattern with different numbers. Robinson uses 52 kg plus 1.9 kg per inch for men, Miller uses 56.2 kg plus 1.41 kg per inch, and Hamwi uses 48 kg plus 2.7 kg per inch.
The formula adds a fixed 2.3 kg per inch, so weight rises linearly with height. Body weight at constant shape actually grows faster than linearly, roughly with height squared as BMI assumes, or even closer to height cubed for geometrically similar bodies. The linear rule works reasonably between about 5 feet 4 inches and 6 feet 2 inches, but for very tall men it gives weights that correspond to a low BMI. Below 5 feet the calculator holds the answer at 50 kg because the formula was never defined for shorter heights.
A BMI range gives a band of acceptable weights at each height, while Devine gives one point. For a man of 175 cm, the international BMI band of 18.5 to 24.9 spans about 57 to 76 kg, and the Devine figure falls inside it. Neither accounts for body composition. A man who lifts weights may be healthy well above the Devine figure, while a man at the figure with a large waist may still carry excess abdominal fat. Waist measurement adds useful information to either number.
Arjun is a 6-foot-tall college basketball player whose height is recorded as 180 cm in his sports certificate. His coach asks him to note his Devine reference weight.
Answer: Estimated ideal weight 75 kg
Treating the figure as a precise target and ignoring muscle mass and frame size.
Measuring height with shoes on, which adds 2 to 3 cm and raises the answer by about 2 kg.
Using feet and inches written as a decimal, such as 5.8 for 5 feet 8 inches, when converting to centimetres.
Applying the adult formula to teenagers who are still growing.
Getting a quick reference weight to discuss with a doctor or trainer.
Clinical calculations of ideal body weight for some drug doses and ventilator settings, done by professionals.
Cross-checking a BMI-based weight goal with a second method.
Physiology and nursing students practising the classic IBW formula.
Is this the weight I should aim for?
Treat this as a rough guide, not a strict target. A healthy weight depends on your build and muscle mass, which a height-only formula cannot fully capture.