Convert from marc [France] to oncia [Italy]

Unit Definition (marc [France])
The marc is a traditional units of weight in various countries of Western Europe. In each country the unit equals 1/2 the unit corresponding to the English pound. Thus the French marc equals 1/2 livre, 8 onces or about 244.75 grams; the Spanish marco equals 1/2 libra or about 230 grams; the German mark equals 1/2 pfund or about 280.5 grams; and the English mark equals 8 ounces or 226.8 grams. The English unit was used almost entirely for measuring precious metals.

Unit Definition (oncia [Italy])
The onça, once, oncia, onza is traditional names for the ounce unit in Romance languages. The Italian oncia or onza is no longer used, but traditionally it equaled 1/12 libra or about 27.3 grams (0.96 ounce).