Retaining Wall Calculator

Blocks per course (wall length ÷ block length, rounded up) × number of courses (wall height ÷ block height, rounded up), plus a waste allowance for cuts at corners and ends.

Cap stones finish the top course of the wall with a flat, clean edge — they replace the top field-block course rather than adding an extra one.

A compacted gravel leveling pad, typically 6 inches deep and about twice the block depth wide, running the full wall length, plus about 20% for compaction.

For walls over about 4 feet tall, or any wall holding back a significant slope or load (a driveway, structure, or standing water), have a structural engineer confirm the design and drainage.