Meters
When discussing length, distance or other types of two-dimensional measurements such as thickness and height, meters are the standard unit. By multiplying or dividing a meter, all other forms of measurement, such as centimeters, millimeters and decimeters, are created. Meters are expanded or reduced by factors divisible by 10. A centimeter is 1/100th of a meter and millimeters are 1/1000th of a meter. The prefix affixed before "meter" provides the defined length; "centi" means 1/100th. A meter is roughly equivalent to 3.28 feet.
Kilometers
Kilometers are exactly equal to 1,000 meters. The prefix "kilo" means one thousand. This is why a kilogram means 1,000 grams or a kilowatt is equal to 1,000 watts. Kilometers are used to measure distance as opposed to basic length. A single object is rarely long enough to warrant being measured in kilometers. One kilometer is roughly equivalent to 0.62 miles. Kilometers are used in Europe and other parts of the world as miles are used in the United States. The distances between towns, measuring traveled distance and the rate at which a vehicle travels (kilometers per hour) all use kilometers as their base unit.
Converting from Meters to Kilometers
Because there are 1,000 meters in a single kilometer, converting from meters to kilometers is simple. This is one benefit of the metric system: ease of use when converting between smaller and larger units. The math to convert meters into kilometers is as follows: divide the amount of meters by 1,000. If something is 500 meters long, divide 500 by 1,000 to convert it into kilometers. The answer here is 0.5 kilometers.
Converting from Kilometers to Meters
To transfer from kilometers into meters, you must do the opposite of what you do to convert the reverse. This is true with all conversions. To move in the opposite direction, you must reverse any mathematical operations. Instead of dividing meters by 1,000, you must multiply kilometers by 1,000 to convert to meters. A distance of 100 kilometers, when multiplied by 1,000, is equal to 100,000 meters. Try to remember that "kilo" equals "one thousand" in an effort to keep these conversions in your head. One "kilo"-meter is the same as a "one thousand"-meter.