Retaining Wall Calculator
Plan the basic materials for a segmental retaining wall. Enter wall dimensions and the face size of the block to estimate rows, blocks, cap units and gravel volumes.
Enter project details
Planning estimate only. Confirm local prices, supplier specifications and site conditions before ordering.
Your estimate
Block, base and backfill quantities are material estimates only. Wall height, drainage, reinforcement and structural requirements must follow the wall system and local conditions.
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Tell us about your retaining wall installation project. ProjectMetrica uses WiserLeads, the Triares/homeyou lead platform, to check whether a participating buyer is available for your project.
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How the retaining wall calculator works
Blocks per row = wall length ÷ block face width. Rows = wall height ÷ block face height. Total blocks = rows × blocks per row, plus waste.
For a better estimate
- Use the installed face dimensions of the block, not package dimensions.
- Real walls may require buried courses, corners, cuts, drainage pipe and geogrid.
- Structural walls should follow the block manufacturer’s engineering guidance and local requirements.
Tools that can help with this project
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Frequently asked questions
How many retaining wall blocks do I need?+
Divide the wall length by the block face width, multiply by the number of rows, then add waste for cuts and breakage.
Does the calculator include buried blocks?+
The estimate is based on visible wall height. Add any buried base course required by the block system and site conditions.
Does a retaining wall need drainage gravel?+
Many segmental retaining walls use free-draining aggregate behind the wall, but details vary by design and manufacturer.