The inch is one of the standard units of measurement used in many countries, including the United States. In relation to other non-metric measurements, there are 12 inches in one foot and 36 inches in one yard. In order to convert inches into the metric system, you only need to perform a simple mathematical operation.
Write down the number of inches you want to convert to the metric system.
Multiply the number recorded in Step 1 by 2.54.
Change the units on the result of Step 2 to centimeter. You can now convert easily between other metric units, including the millimeter (equal to 1/10th of a centimeter) and the meter (equal to 100 meters).