Retaining Wall Calculator

Estimate how many retaining wall blocks you need from wall length, height, and block size. Includes a buried base course, cap row, and waste factor for accurate ordering.

Wall Length (ft)Wall Height (ft)Block Length (in)Face length of one block, 18 in is commonBlock Height (in)Exposed height of one course, 6 in is commonCap Length (in)Length of each cap unit, often shorter than the wall blockWaste (%)

Include buried base courseInclude cap course

Results are estimates for material ordering, not a structural design. For walls that hold back a slope, driveway, or structure, or that exceed about 3 to 4 ft in height, consult a structural engineer or your local building department before you build.