Retaining Wall Calculator
Calculate how many blocks you need to build a retaining wall.
Assumptions used in this calculation
- Wall face area only: Counts blocks to cover the visible wall face area, it doesn't add extra blocks for the buried base course, footing, or corner/cap blocks.
- No engineering check: Doesn't verify wall height against engineering limits for unreinforced gravity walls, taller retaining walls (typically above 3-4 ft) usually require engineered design and permits.
About this calculator
The retaining wall calculator divides total wall area by the footprint of a single block to find how many blocks are needed, including a waste allowance for cuts and breakage.
Worked example
30ft long, 3ft high wall, 16×8in blocks, 10% waste
Result: ≈ 112 blocks
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