Imperial BMI Formula (Weight (lbs.) * 703) / Height (inches) 2. When using pounds and inches, the formula needs to be altered slightly. Multiply your weight in pounds by 703.

Step 3: Calculate your BMI using the formula: Weight in kilograms divided by the square of height in meters, i.e. weight (kg) / [height (m)]2 Example: Weight = 60 kg, Height = 166 cm (1.66 m) ...