Body Composition
Devine formula (1974)
The version written for drug dosing. The base is 50 kg for men and 45.5 kg for women, and the increment applies only to inches above five feet.
The Formula
IBW = base + 2.3 x (height in inches - 60)
The version written for drug dosing. The base is 50 kg for men and 45.5 kg for women, and the increment applies only to inches above five feet.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| base | Sex constant: 50 kg for men, 45.5 kg for women | kilograms | A fixed starting weight, not a measurement of the person. |
| h_in | Height in inches | inches | Metric heights must be divided by 2.54 before use. |
| IBW | Estimated reference weight | kilograms | The figure used to scale drug doses, not a health target. |
What Each Symbol Means
basekilograms
Sex constant: 50 kg for men, 45.5 kg for women
A fixed starting weight, not a measurement of the person.
h_ininches
Height in inches
Metric heights must be divided by 2.54 before use.
IBWkilograms
Estimated reference weight
The figure used to scale drug doses, not a health target.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate ideal body weight page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Ideal Body Weight, filed under Health. Every number the guide produces comes from substituting into this one line.