One of the first steps in the planning process is to determine the quantity of materials needed. This begins with determining how much roadway is to be covered.

The length and width of roadway to be seal coated must be determined to estimate material quantities. The length of the roadway should be obtained using the station numbers or a distance-measuring instrument (DMI).

Once the longitudinal distance has been determined, the area is computed by multiplying the longitudinal distance (length) by the width of the road, in feet. This total area will be expressed in square feet and must be converted to square yards by dividing the total area by 9. Asphalt application rates are expressed in gallons per square yard, and aggregate application rates are based on cubic yards (of aggregate) per square yard of roadway.

If different materials will be used on the shoulders, they should be calculated separately. To promote cost savings, a TxDOT directive states to limit seal coat on shoulders four feet or greater in width to every other seal coat cycle. Crack sealing on shoulders should be used as part of the overall maintenance plan and is a less expensive means of keeping water out of the substructure.