Common units for measuring distance include meters, feet, inches, yards and miles. The metric system uses the word "meter" along with a prefix that designates a multiple of ten. Standard units, common in the United States, use different words that are related by a different multiple.
In the United States, the smallest common unit of distance is referred to as an inch. Twelve inches are equal to one foot. Three feet is referred to as a yard. A distance of 5,280 feet is referred to as a mile, the largest common standard unit.
Outside of the United States, distance is more commonly measured by the International Standard of Units. The SI unit for distance is a meter. There are many prefixes used to designate much larger or much smaller units. The commonly known prefixes range from giga, which is an increase by a multiple of one billion, to nano, which is a decrease by a multiple of one billion. The most common metric measurements are the millimeter, which is equivalent to 0.001 meters, the centimeter, equivalent to 0.01 meters, and the kilometer, equivalent to 1000 meters. United States measurements and SI measurements can be converted back and forth. One meter is equivalent to 3.28 feet.