Retaining wall calculator
Count full course positions for a simple segmental wall.
Formula
Blocks = ceil[ceil(L/block L) × ceil(H/block H) × (1+extra/100)]
Wall length: 20 ft · Facing height including burial: 3 ft · Installed module length: 16 in · Installed course height: 8 in · Blocks per course ≈ ceil(((20 ft × 0.3048 m/ft)÷(16 in × 0.0254 m/in))×(1-8.881784197001252e-16)) · Courses ≈ ceil(((3 ft × 0.3048 m/ft)÷(8 in × 0.0254 m/in))×(1-8.881784197001252e-16)) · Blocks with spares ≈ ceil(((15)×(5)×(1+(5)÷100))×(1-8.881784197001252e-16))
How to use
- Enter wall length and height including buried courses.
- Enter installed face module dimensions.
- Set spares and read courses and blocks.
Examples
- A 6 × 1 m wall with 40 × 20 cm modules uses 75 blocks before spares.
Frequently asked questions
Does height include the cap?
Exclude separate caps; include all buried facing courses specified by the plan.
Does this design the wall?
No. Loads, soil, drainage, reinforcement and embedment require a project design.
What about curves and steps?
This is a straight uniform wall. Caps, corners, setbacks and stepped foundations need separate takeoffs.
Sources
Updated: