How do you figure up how many cinder blocks you need?

Calculate the exterior face area of he wall you want to build and the face area of the side of the cinder block (add about 1/2 inch to length and 12 inch to width for mortar thickness).

Divide the wall area by the block area This is the number of blocks you require.

This is how I figure out how many blocks you will need: First measure the length of walls for the blocks in feet. Second divide that number by 4 then multiply the total by 3. That will give you total blocks needed for one course of blocks.