What is the difference between porcelain and ceramic tile? 

Porcelain Tile comprised of 50% feldspar and fired at a much higher temperature than standard ceramic tile, resulting in a much harder and more dense product that is resistant to scratches and can withstand temperature extremes. Also, stain resistant with very low water absorption.

Biocuttura Tile Ceramic tiles are fired in a kiln at temperatures of around 2,000 degrees Fahrenheit. These tiles are first fired after the green tile dries and then again after glaze is applied. Also call Double Fired.

- World Floor Covering Association
www.wfca.org

How do I calculate square footage for tile?
Use this square footage calculator by the World Floor Covering Association to get an estimate of material

What size of tiles should I use for a shower floor?

In order to retain the best slip resistiance and proper draining, tiles measuring approximately 3"x3" or less are reccomended for shower floors.