Before you start to calculate 2 Gallons, you should know the conversion rate between Gallons and Cubic Inch.
The rate is 2.783349E-13 and the math equation is 2 X 2.783349E-13 = 5.566698E-13 .
Quick conversion chart of Gallons to Cubic Inchs
1 Gallon to Cubic Inch = 2.783349E-13 Cubic Inch5 Gallon to Cubic Inch = 1.3916745E-12 Cubic Inch10 Gallon to Cubic Inch = 2.783349E-12 Cubic Inch20 Gallon to Cubic Inch = 5.566698E-12 Cubic Inch30 Gallon to Cubic Inch = 8.350047E-12 Cubic Inch40 Gallon to Cubic Inch = 1.1133396E-11 Cubic Inch50 Gallon to Cubic Inch = 1.3916745E-11 Cubic Inch75 Gallon to Cubic Inch = 2.08751175E-11 Cubic Inch100 Gallon to Cubic Inch = 2.783349E-11 Cubic Inch