You don't. Cubic inches is a measure of volume and square inches is a measure of area.
Inches cubed x 16.387 = cm cubed
1 Foot = 12 Inches 1 Sq. Foot = 12 Inches Cubed.
1 milliliters = 0.0610237441 inches cubed
Multiply the cubic inches by 16387.064
2.3 cubic feet = 3,974.4 cubic inches
Inches cubed x 16.387 = cm cubed
project your 3D inch onto a 2D surface, you get a square inch.
1 Foot = 12 Inches 1 Sq. Foot = 12 Inches Cubed.
1 milliliters = 0.0610237441 inches cubed
Multiply the cubic inches by 16387.064
2.3 cubic feet = 3,974.4 cubic inches
Neither. It is just inches. Area is square inches, Volume is inches cubed.
To convert square inches to square mm, multiply square inches by 645.16
8*10*5 = 400 inches cubed (...square inches are when the object has two dimensions, and inches cubed when the object has three dimensions...) 400
If you are trying to find pound per square inch cubed, you would just divide the pound per foot cubed by 12x12x12 (1,728). One foot cubed is equal to a block of cubed inches 12x12x12, correct? Then you just add on the "pound per" measurement and you have your answer.
To convert from square inches to square cm, multiply by 6.452.
You cannot convert square inches to inches. Square inches are units used to measure area and inches are units of length. You cannot convert one to the other.