Multiplying the length, width and depth, converted to yards, of the area in question provides the amount of concrete needed in cubic yards. This formula is applicable for any square or rectangular area, commonly referred to as a slab when pouring concrete.

This formula provides an approximation of how much concrete is needed in a designated area. Those preparing to lay down new concrete should round the calculated number up in order to account for differences in depth and spillage. Once the measurements are collected, there are several online tools that allow the user to calculate the cubic yards as well as the number of pre-mixed concrete bags needed to fill the area.