Estimate how many retaining wall blocks you need. Each dimension has its own unit selector (in/ft/yd/m).
Retaining wall blocks are estimated by the face area of the wall (length times exposed height, any unit). Divide by the face coverage of one block, or enter blocks-per-square-foot directly - the preset covers common sizes. Most segmental blocks dry-stack over a compacted gravel base; add about 5% for breakage.