A magnum is used as a unit of measurement in measuring the quantities of wines, champagnes, beers and other alcoholic beverages. One magnum is capable of holding 1.5 liters of liquor. 1.5 liters on the other hand, is equal to two standard bottles of Champagne. An average Champagne serving is equivalent to four ounces and a regular bottle of champagne can fill six 4 ounce flutes. Thus, 12 four once flute glasses of champagne can be filled by a magnum.