The tool to the right will allow you to calculate the total cost of concrete per yard. To use this tool please enter in size of the concrete bags that you are going to purchase along with the cost per bag of concrete for your area. Estimate the number of bags that you expect to use for your project and enter them into the "cost per bag" field. Next click the calculate button. You will notice that the results will appear in the fields below the calculate button. Continue to adjust the number of bags of concrete until you reach the desired number of cubic feet of your concrete slab or structure. Through trial and error you will be able to calculate the total concrete cost per yard for your project as well as the number of bags necessary to complete the project. Continue to adjust your results by increasing the bag size. Some concrete vendors will sell larger bags of concrete for a lower price per cubic inch then smaller bags. As such, you should adjust your results until you are using the largest concrete bag size possible. Please not that the price of concrete can vary with region.