To convert 38 kilograms to pounds, it is necessary to multiply it by 2.205, making the answer 83.79. To invert the calculation from pounds to kilograms, simply multiply the number of pounds by 2.205.
Because 2.205 is a hard number to use without a calculator, many people just multiply the number of kilograms by 2.2 to make the mental arithmetic easier. Louis XVI of France ordered a group of savants to create a new, more precise measure of weight, called the "gramme." The savants used a liter of water at freezing point to denote 1 kilogram because it was easier to work with larger objects than smaller ones.