A patient weighing 180 pounds needs to be converted to kilograms for dosing calculations. Approximately how many kilograms is this weight?

• A. 72 kg
• B. 82 kg
• C. 90 kg
• D. 100 kg

Answer: (B)

Converting pounds to kilograms uses the standard factor that 1 kilogram is about 2.2 pounds. To get kilograms, divide the weight in pounds by 2.2. So 180 pounds divided by 2.2 equals about 81.8 kg, which rounds to 82 kg.

The other numbers don’t match the same conversion: 72 kg corresponds to about 158 pounds, 90 kg to about 198 pounds, and 100 kg to about 220 pounds. Since 180 pounds is closest to 82 kg, that’s the appropriate approximation for dosing calculations.