One of the most important things in completing your new concrete project is determining the correct amount of concrete for your project. To make this important step a little easier, Harrison has created a Slab, Column and Stairs Calculator for you. How to figure concrete for your next project has never been so easy! Simply plug in the required fields for your project and click the "Calculate" button. The calculators will estimate approximate total yards needed to complete your project. Also, you may want to add 5% more concrete to your total cubic yards in order to allow for waste, spills and other minor excavation overages. Simply call 865-934-6500 and provide your Total Cubic Yards of Concrete Required to the Harrison dispatcher sales representative and we will conveniently arrange a delivery time. Unload and pour tips. Ask the Harrison sales representative about normal unload times. If for some reason the truck can not reach the unload area, make sure you have two or three people with wheelbarrows ready to help. This Calculator should be used as an estimating tool ONLY. Harrison is not responsible for any discrepancies in materials ordered based on calculations made with this application.