Find an ideal body weight range, based on your height.
The Devine formula, originally developed for medication dosing, widely repurposed as a general ideal-weight estimate.
Men: 50kg + 2.3kg per inch over 5 feet
Women: 45.5kg + 2.3kg per inch over 5 feet
The ideal weight calculator gives an estimate of a reasonable body weight for your height and sex using the Devine formula. It starts from a base weight at five feet tall, 50 kg for men and 45.5 kg for women, and adds 2.3 kg for every inch above that.
The number is a reference point, not a goal you must hit. Doctors and pharmacists still use formulas like this when a dose depends on body size, and many people find it a helpful anchor alongside a BMI range. Because it uses only height and sex, it cannot see frame size, muscle or where fat sits, so a healthy weight for you may be several kilograms either side. Comparing it with the healthy BMI range for your height gives a fuller picture.
1. Measure your height in centimetres.
2. Convert to inches by dividing by 2.54.
3. Subtract 60 inches, which is five feet. If the result is negative, use zero.
4. Multiply the inches over five feet by 2.3 kg.
5. Add the base: 50 kg for men, 45.5 kg for women.
6. Ideal weight = Base + 2.3 × (Inches − 60).
Dr B. J. Devine proposed the formula in 1974 to estimate body weight for calculating doses of certain medicines, not as a beauty or fitness target. It spread into general use because it is simple and gives sensible numbers for average adult heights. Other formulas from the same era, such as those of Robinson, Miller and Hamwi, use slightly different bases and slopes, and give results that can differ by a few kilograms for the same person.
The formula was written in American units: a base weight at 60 inches, plus a fixed amount per inch. That is why the calculator converts centimetres to inches first. The result is a straight line: every extra inch, or 2.54 cm, adds 2.3 kg regardless of how tall you already are. BMI, by contrast, grows with height squared, so for tall people the Devine value usually sits lower in the healthy BMI range than for shorter people.
The formula has no term for being shorter than 60 inches, which is 152.4 cm. The calculator sets the extra inches to zero in that case, so everyone at or below five feet gets the base value: 50 kg for men and 45.5 kg for women. For shorter adults, which includes many Indian women, this can be higher than a healthy BMI-based figure. In that situation, the healthy BMI range for your height is a better guide.
Divya is 158 cm tall and wants a reference weight to discuss with her dietitian alongside her BMI range.
Answer: Estimated ideal weight 50.6 kg
Treating the result as an exact target instead of the centre of a reasonable range.
Applying the formula to children or teenagers, for whom it was never intended.
Ignoring frame size and muscle: a muscular person can be healthy well above this number.
Using it for heights under five feet without noticing that the result stops falling below 152.4 cm.
A quick reference weight alongside a BMI range.
Clinical estimates where medicine doses depend on body size.
Setting a starting discussion point with a doctor or dietitian.
Teaching how empirical formulas are built from population data.
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, muscle mass, and body shape, which this simple height-only formula cannot fully capture.