gallons, volume is that in both systems, conventional American and Royal British in three different amount is used. In the UK, Canada and some countries in the Caribbean from gallon Imperial or gallon Royal use to be, which is almost equal to 4. the 546092 liters can be. "A gallon of American" for the liquid material in the U.S. and some Latin American countries, that of Japan, almost 3. the 785412 liter. A gallon of American, that for a solid material that is rarely used that value almost 4. the 40 liters can be. In Iran, per gallon 3/78 liters can be.