How Can You Calculate the Amount of Asphalt You Need for a Project?
Determine the surface area of the space you are paving, and multiply by the desired thickness in feet to calculate the volume of asphalt required in cubic feet. Multiply the volume by density to determine weight and convert to tons. The calculations require a few minutes for small projects.

Calculate the surface area
Measure the area with a tape measure. Convert all measurements to feet. Use the appropriate geometric formula to calculate the area. For rectangles, multiply length by width. For odd shapes, divide the project into smaller shapes, calculate the area of each small shape, and find the total.

Find the volume
Divide the thickness in inches by 12 to convert it to a fraction of a foot. Multiply the result by the surface area to determine volume in cubic feet.

Determine the amount
Asphalt density varies based on the composition and size of aggregate. The supplier you use provides this information for its product in pounds per square foot. Multiply the volume by the density to determine the pounds of asphalt the project requires. Divide the pounds by 2,000 to determine the number of tons of asphalt to order. If the supplier sells asphalt by the cubic yard, divide the volume by 27 to determine the number of cubic yards to order.