A centimeter is a metric measure equal to one hundredth of a meter. One centimeter is approximately 0.394 inches. Legend has it that a centimeter is the average width of a nail in an average person. Here you can convert inches to centimeters using our simple and handy online calculator. It is free and fast! Such a calculator will be very useful if you live in a country that uses a metric system of measures. For example, you can calculate the diagonal of your screen in centimeters.