Bricks vary in weight depending on their material, manufacturing process and size. At Nash Brick, a solid modular brick that is 7 5/8 inches long, 3 1/2 inches wide and 2 1/4 inches high weighs 4.3 pounds. A Watsontown brick with identical dimensions weighs 4.9 pounds.
A Watsontown standard solid brick that is 8 inches long, 3 1/2 inches wide and 2 1/4 inches high weighs 5 pounds. A Watsontown cored standard brick weighs 4.1 pounds. A cored brick has one or more holes that are punched through the top of the brick.
Bricks made from expanded clay aggregate or fly ash can be significantly lighter than other brick types.