How many cubic inches in a gallon?
There are 231 cubic inches in a gallon. To convert gallons to cubic inches, multiply the gallon value by 231.
For example, to find out how many cubic inches in a gallon and a half, multiply 1.5 by 231, that makes 346.5 cubic inches in a gallon and a half.
1 US Fluid Gallon = 231 Cubic Inches
What is a Gallon?
Gallon is an imperial and United States Customary measurement systems volume unit. 1 US fluid gallon is equal to 231 cubic inches and 1 Imperial gallon is equal to 277.419 cubic inches. The symbol is "gal".