How to Calculate Concrete
First figure out how much space you need to fill with concrete. After that, figure out how many bags of dry concrete you need to fill that space. Using the example of pouring a long, narrow concrete slab for a backyard chicken coop helps you learn how to calculate concrete.
Calculate How Much Concrete You Need For Common Projects
Concrete Slabs
To pour a 100 square foot concrete slab for patios or sheds, you’ll need: Example: The chicken coop’s slab will be 20 feet long and 5 feet wide. Multiply 20 by 5. The area is 100 square feet. Example: The chicken coop’s slab will be 6 inches thick. Six inches is the same as 0.5-foot. So, the depth of the slab will be 0.5-foot. Example: 100 square feet of area multiplied by 0.5-foot depth is 50 cubic feet. So, to fill the coop’s form, you will need 50 cubic feet of wet, mixed concrete. But how many bags of dry concrete should you buy? Example: The chicken coop form needs to be filled with 50 cubic feet of wet concrete. Multiply 50 by 133.33 to arrive at 6,666 pounds of dry concrete mix needed. Example: The coop slab needs 6,666 pounds of dry concrete. You found a good price on palletized 80-pound bags of fast-mix concrete. Dividing 6,666 by 80 produces the rounded up number of 84. So, for the slab, you need 84 bags (or two pallets) of 80-pound concrete. The number of 50-pound bags of dry concrete you will need for the following configurations is:
