Estimate a straight, single-face wall
Enter the total block height, including any buried courses. Use the manufacturer’s face dimensions for blocks and effective coverage length for caps. The tool rounds blocks per course and course count up before applying the order allowance. It assumes a straight wall of uniform height with one cap row.
Base and drainage stone
The base is modeled as a rectangular trench. Drainage stone is modeled as a rectangular strip behind the wall over the entered total wall height. Defaults illustrate estimating only. Enter dimensions from the approved design and supplier instructions. Block-core fill, wider reinforced zones and overlapping volumes are not included.
Formula and example
Blocks = ceiling(ceiling(length × 12 ÷ block length) × ceiling(height × 12 ÷ block height) × allowance factor). Caps are rounded up from wall length and cap length, then allowance is applied. Base yards = length in feet × trench width in inches × base depth in inches ÷ 3,888 × allowance factor. Drainage yards = wall length × total height in feet × drainage thickness in inches ÷ 324 × allowance factor.
Material estimate only
This calculator does not design or certify a retaining wall. It does not evaluate soil, slope, loads, drainage, footing, reinforcement, geogrid, setbacks or permits. Curves, corners, steps and multiple wall faces require a separate takeoff. Follow the wall manufacturer’s design guidance and obtain professional design or local approval when required.
Reference: Allan Block retaining-wall resources.
Comparing bulk stone prices? Read the yards-to-tons guide, then use the gravel calculator or sand calculator for separate layers.