So, a cup is then 0.22 liters (or 2.2 deciliters, 22 centiliters, or even 220 milliliters). Heck, I have tea-cups twice that size
cup (c) a traditional unit of volume used in recipes in the United States. One cup equals 1/2 (liquid) pint, or 8 fluid ounces. Technically, one cup equals exactly 14.4375 cubic inches or approximately 236.6 milliliters, not that anyone measures quite so precisely in the kitchen. American cooks use the same size cup for measuring both liquid and dry substances. In Canada, a cup is equal to 8 Imperial fluid ounces (13.8710 cubic inches or 227.3 milliliters). In Britain, cooks sometimes used a similar but larger unit called the breakfast cup, equal to 10 Imperial fluid ounces. The British cup equals 1/2 Imperial pint, but the Canadian cup is only 0.4 Imperial pint. cup (c) an informal metric unit of volume equal to 250 milliliters, commonly used in recipes in Australia.
(But you were pretty spot on with the gallon thing)
Just kidding with you guys off course ^^ didn't mean to pull the thread OT, I'll shut up now