One thousand meters make up one kilometer. The prefix "kilo" denotes multiplication by 1,000, and the meter is the International Systems of Units basic measure for length. Combining the two yields one thousand total meters.
Likewise, one kiloliter is 1,000 liters, and one kilogram is 1,000 grams. Reversing the operation shows that one meter is one thousandth of a kilometer, one liter is one thousandth of a kiloliter, and one gram is one thousandth of a kilogram. To convert meters to kilometers, divide by 1,000, and to convert kilometers to meters, multiply by 1,000. The same method may be used to convert liters and grams.