It would be a shame to buy too much or, even worse not enough materials and have to go back to the home improvement store. x Area 3 Width SEARCH: How to use Clear Map Create Overlay Pre . These can be in metric units (centimeters or meters) or imperial units (yards, feet or inches). Rolls of sod cost between $0.34 and $0.85 per square foot on average depending on the type of grass selected and amount purchased. 30 percent compost. ft. ft. = 5,662.8 sq. Multiply these 2 numbers together to get total square feet. Just type the density of soil (you will probably find it on the packaging) into the topsoil calculator, and this calculation will be performed effortlessly. Whether you want to work in metric units (centimeters and meters) or imperial units (feet, yards or inches), our calculator can help!