Convert from ounce to tonne

Unit Definition (ounce)
The ounce is a traditional unit of weight. The avoirdupois ounce, the unit commonly used in the United States, is 1/16 pound or about 28.3495 grams. The avoirdupois ounce also equals 175/192 = about 0.911 457 troy ounce or 437.5 grains. The word ounce is from the Latin uncia, meaning a 1/12 part, because the Roman pound was divided into 12 ounces. The word "inch," meaning 1/12 foot, has the same root.

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.