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.
Request a local retaining wall quote
Complete three short steps to check for available local professionals.
Free to submit No purchase required
ProjectMetrica helps route your retaining wall installation request to participating platform partners or service providers when an eligible match is available.
- Availability depends on ZIP code, service and project details.
- ProjectMetrica is not the contractor and may receive compensation for an accepted request.
ProjectMetrica collects this request and may share it with participating service providers and platform partners for the home-improvement project you selected. The consent session is independently recorded. See the Privacy Policy.
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
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases.
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.