One cubic yard of topsoil weighs approximately 1,080 pounds. This estimate is based on the calculation that 1 cubic yard equals 27 cubic feet. One cubic foot of topsoil weighs approximately 40 pounds. These weights are estimations based on available data. The exact weight will depend on various conditions.
The estimation of 1 cubic foot weighing 40 pounds is based on bags of topsoil. Some bags state a weight of 40 pounds, and some state a volume of 1 cubic foot. The dimensions of the contents are similar. Other factors determining weight are moisture content and volume of sticks, rocks and other debris.