That depends on the type material you are referring to. Also, these are two different types of measurements. One is volume the other is length or distance. Please edit your question to include more context or details.
3785.4117841 US gallon = 3,785.4 cubic centimeters
1 US gallon equals slightly more than 3785.4 cubic centimeters.
1 US gallon = 3,785.41cc (cubic centimeters).
In one US gallon there are 3,785.412 cm^3.
1 US gallon equals 3,785 cc, and 1 imperial gallon equals 4,546 cc.
1 US gallon = 3,785.41 cm3 (rounded)
1 US gallon = 3785.41178 cc
3,785.4 cm3
1 US gallon = 3,785.41 cubic centimeters (rounded)
3 785.411 784 cubic centimeters, 0 square centimeters
5 centimeters=0.5 decimeters
You cannot compare them directly: a gallon is a unit of volume while centimeters are length.However, a gallon is very much larger than the volume 15 cubic centimeters (cc).There are 3785.4 cubic centimeters to the US gallon.