Math & Trig
BMI calculation formula: metric (kg/cm), imperial (lb/in), and categories
Calculate Body Mass Index from kilograms and centimeters or pounds and inches, and assign adult screening bands with IFS.
Convert centimeters to meters before squaring
Metric BMI is defined as weight_kg / (height_m ^ 2). When height is recorded in centimeters (such as 180 cm), divide by 100 inside parentheses first: A2 / ((B2 / 100) ^ 2).
For US customary units (pounds and total inches), multiply weight divided by inches-squared by the standard conversion factor 703: 703 * WeightLb / (HeightIn ^ 2).
This is an educational calculation for adults aged 20 and older, not a diagnosis. BMI is a screening measure with limitations, including for muscular people; children require age- and sex-specific assessment. Require positive numeric height and weight and use unrounded BMI for category thresholds.
| WeightKg (A) | HeightCm (B) | Metric BMI | WeightLb (C) / HeightIn (D) | Imperial BMI |
|---|---|---|---|---|
| 72 | 180 | 22.2 | 154 lb / 70 in | 22.1 |
Metric and imperial BMI formulas
At 72 kg and 180 cm (1.8 m, squared = 3.24), BMI equals 72 / 3.24 = 22.22 -> 22.2. At 154 lb and 70 in (4,900 sq in), 703 * 154 / 4900 = 22.09 -> 22.1.
=ROUND(A2 / ((B2 / 100) ^ 2), 1)Classify adult BMI ranges with LET and IFS
Ordered left-to-right thresholds (< 18.5, < 25, < 30, else TRUE) map continuous BMI values into the adult categories used by CDC without nested IFs.
=LET(bmi, A2 / ((B2 / 100) ^ 2), IFS(bmi < 18.5, "Underweight", bmi < 25, "Healthy weight", bmi < 30, "Overweight", TRUE, "Obesity"))Try the example
Use the original values or change them to test your understanding.