A fluid ounce (abbreviated fl oz, fl. There are 31.1035 grams per troy ounce. The standard version has a weight of minimum 1 troy ounce (31.10 grams). The standard version has a weight of 1 troy ounce (31.10 grams). Soda comes in 14 flavors available in 12 ounce cans. Soft drinks typically contain 0 to 55 milligrams of caffeine per 12 ounce serving. Ralston found about 1/4 ounce (6 g) of gold, then worth about five dollars. The milk contains about 92 cal per ounce. Add about 1 ounce of whiskey and stir again. A troy ounce is equal to 480 grains. The avoirdupois ounce is lighter than the troy ounce; . Multiple pounds based on the same ounce were quite common. There are 24 grains in 1 dwt, and 20 dwt in one troy ounce. Beer is sold in fluid ounce denominations. The Government applied a gold tax of two shillings and sixpence an ounce.