how to calculate concrete slab cost
We'll use a 10 x 10 ft. slab as an example. Here's a brief rundown of what you need to know. Amount. Calculate the volume you need in cubic yards. Multiply the length (10 ft.) by the width (10 ft.) by the depth (.35 ft., or 4 in.) and divide it by 27 (the number of cubic feet in a cubic yard).You get 1.3 cu. yds. Then add 10 percent to allow for spillage and slab depth variations. Strength.e'll use a 10 x 10 ft. slab as an example. Here's a brief rundown of what you need to know. Amount. Calculate the volume you need in cubic yards. Multiply the length (10 ft.) by the width (10 ft.) by the depth (.35 ft., or 4 in.) and divide it by 27 (the number of cubic feet in a cubic yard).