Convert from tonne to kilogram

Unit Definition (tonne)
The tonne is a metric unit of mass equal to 1000 kilograms or approximately 2204.623 pounds avoirdupois. The SI uses this French spelling for the metric ton to distinguish it clearly from the long and short tons of customary English usage. Large masses are often stated as multiples of the tonne, although technically the SI requires that masses be stated as multiples of the gram. Thus a mass of 10³ tonnes = 10⁶ kg = 10⁹ g is often called 1 kilotonne (kt) instead of 1 gigagram. In the United States, the Department of Commerce recommends that the tonne be called the metric ton.

Unit Definition (kilogram)
The kilogram is the base unit of mass in the SI and MKS versions of the metric system. The kilogram is defined as the mass of the standard kilogram, a platinum-iridium bar in the custody of the International Bureau of Weights and Measures (BIPM) near Paris, France. Copies of this bar are kept by the standards agencies of all the major industrial nations, including the U.S. National Institute of Standards and Technology (NIST). One kilogram equals exactly 1000 grams, or about 2.204 622 6 pounds. By design, this is approximately the mass of a liter of water.