Retaining Wall Calculator
Enter your wall length, height, and block size — get blocks, caps, courses, and the gravel base you need.
Block count includes ~5% for cuts. Walls over ~3–4 ft usually need engineering, geogrid, and a permit. Bury the bottom course ~10% of wall height and backfill with gravel + a drain.
How the retaining wall calculator works
Blocks = wall face area ÷ block face area, plus 5%. Face area is length × height. Caps run along the top — about one per block width. Courses are wall height ÷ block height.
The base and drainage matter more than the blocks
A wall fails from water and a bad base, not from too few blocks. Set the first course on compacted gravel in a level trench, bury it about a tenth of the wall height, and put gravel backfill plus a drain pipe behind it so water never builds up.
Building a wall that has to hold?
We build block retaining walls for erosion and grade changes across North Port, Venice, Port Charlotte & Englewood — with the base and drainage done right.
Our Retaining Walls →