How this calculator works
The calculator converts wall height and block height into a row count. Blocks per row are wall length divided by block length, rounded up. Wall blocks are rows times blocks per row with waste added. Cap blocks are cap rows times blocks per row with waste, and drainage gravel uses a 1 ft thick zone behind the exposed wall as a rough planning estimate.
Example: a 30 ft wall that is 3 ft high with 16 in by 6 in blocks needs 6 rows. At 23 blocks per row and 5% waste, the estimate rounds to 145 wall blocks and 25 cap blocks.