The size of a cubic yard of dirt
A cubic yard of topsoil is about the size of a large cooler. It is usually dark brown or black in color and has a crumbly texture. It is composed of organic matter, minerals, and earthworms. Topsoil is essential for growing plants. It provides them with the nutrients they need to thrive.
Watch this video to get a good feel of how much a yard of dirt is and how much you might need for your project (Backyardsccape).