Construction

Retaining Wall Calculator

Estimate blocks for a retaining wall.

Wall length

Wall height

Block length

Block height

Calculated Output

Blocks needed (blocks) 144

Courses (rows) 12

Formula: blocks = (length×12 ÷ blockL) × (height×12 ÷ blockH)

Step-by-Step Breakdown

1. Values used:

2. Wall length = 1

3. Wall height = 1

4. Block length = 1

5. Block height = 1

7. Blocks needed = 144blocks

8. Courses (rows) = 12

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The math behind it

Blocks per row = wall length ÷ block length; rows = wall height ÷ block height; multiply.

30 ft × 3 ft with 12×4 in blocks → 30 × 9 = 270 blocks.

Base course?

Bury the bottom course ~10% of wall height for stability.