A typical concrete block used for building foundations weighs approximately 46 pounds. Many sizes and types of concrete blocks are available; therefore, the weight varies according to the type of block used.
Concrete blocks are strong and durable, making them a good choice for foundation work. They are often quite heavy. In order to help reduce the weight, many are manufactured with two large holes in the center, reducing a foundation block's weight to around 38 pounds. Still lighter, a newer light-weight concrete foundation block weighs only 28 pounds. Corner blocks, cap blocks and concrete bricks are other forms available.