calcs.homes
calcs.homes
Enter your retaining wall's length and height to get block count and gravel base material needed.
Estimate only — excludes drainage pipe, backfill, and geogrid for taller walls.
We find the wall's face area by multiplying length by height, add 10% for cuts and waste, then divide by the face coverage of one block to get a count. The gravel base multiplies trench length, width, and depth to size the leveling bed beneath the first course, converting cubic feet to cubic yards (or cubic meters in metric).
The 10% waste allowance is a standard contractor buffer for cutting blocks to fit corners and end runs without coming up short mid-project. A compacted gravel base matters because it drains water away from the wall and gives the first course a level, stable footing — always check your block manufacturer's install guide for exact base depth and drainage, since requirements get stricter as wall height and soil pressure increase, especially above 3-4 ft (1 m).
Multiply wall length by height for face area, add about 10% for cuts and waste, then divide by the coverage of one block (check the product spec sheet — it's usually printed per pallet).
Many jurisdictions require a permit and engineered design for walls taller than 3-4 ft (1 m). Check with your local building department before starting.