In 1 cubic inch there are 16.387 cubic centimetres.
We know that 2.54 cm is equivalent to 1 inch
2.54 cm = 1 inch
to get to cubic inch you cube the inches thus essentially
( 1 inch x 1inch x 1 inch )
to get to the cubic centimetre you would do the same
( 2.54 cm x 2.54 cm x 2.54 cm) = 16.387