A gallon is a measure of volume, the inch is a measure of length, the two can not be equated.
However the cubic inch and the gallon can be equated, there are 231.00010000000003 cubic inches in one US Gallon.
Gallons is a unit of quantity, inch of length. They cannot be compared
There are 115.5 cubic inches in a half gallon.
1 dry gallon is 268.8 cubic inches.
277.4 cubic inches per UK gallon.
231 cubic inches per US gallon.
One US gallon = 231 cubic inches.
There are approximately 73,921 cubic inches in a 275 gallon cylinder.
One Imperial gallon = about 277.4 cubic inches.
Gallons is a liquid measurement and inches is a solid measurement so there is no such thing as inches in a gallon but there is square inches in a gallon which is completely diffrent. Cubic inches measure volume so a gallon would be measured in cubic inches rather than square inches. 231 cubic inches is equal to one gallon. Answer2 The first para in the above answer is confusing because it says "there is square inches in a gallon". Unfortunately, there are NOT square inches in a gallon - they are CUBIC inches (a measure of volume, not area)
One UK gallon equates to 277.42 cubic inches.
One US gallon = 231 cubic inches.
1 gallon of space = 231 cubic inches regardless of what's in the gallon. Even if it's empty.
231 -- the same as the number of cubic inches in a gallon of any substance. This is a property of gallons, not of specific materials.