Body Composition
BMI in metric units
The standard form. Convert height to metres, square it, then divide weight by that square.
The Formula
BMI = kg / m^2
The standard form. Convert height to metres, square it, then divide weight by that square.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| kg | Body mass in kilograms | kilograms | Total mass of the body; includes muscle, fat, bone and water alike. |
| m | Height in metres | metres | Entered in metres, not centimetres. 175 cm becomes 1.75 m. |
| BMI | Body mass index | kilograms per square metre | A single screening number; it does not measure body fat directly. |
What Each Symbol Means
kgkilograms
Body mass in kilograms
Total mass of the body; includes muscle, fat, bone and water alike.
mmetres
Height in metres
Entered in metres, not centimetres. 175 cm becomes 1.75 m.
BMIkilograms per square metre
Body mass index
A single screening number; it does not measure body fat directly.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate bmi 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 BMI, filed under Health. Every number the guide produces comes from substituting into this one line.