Retaining Wall Calculator – Estimate Materials & Costs
Our retaining wall calculator helps homeowners, contractors, and landscapers quickly estimate the materials, concrete, and costs needed for a retaining wall project. By entering your wall dimensions and material preferences, you get instant breakdowns of block counts, footing concrete volumes, and total project costs. Whether you're planning a small garden wall or a large structural retaining wall, this tool saves time and reduces guesswork.
Total horizontal length of the retaining wall.
Exposed height of the wall above ground.
Thickness of the wall (typical concrete block: 8 in).
Select the primary material for your retaining wall.
Depth of the concrete footing below grade.
Width of the concrete footing (typically 2x wall thickness).
Estimated labor cost per square foot of wall face. Set to 0 for DIY.
Average material cost per square foot of wall face for chosen material.
Your results will appear here
How to Use This Calculator
1. Enter the total length of your retaining wall in feet. 2. Input the desired wall height in feet (the exposed portion above grade). 3. Set the wall thickness in inches — 8 inches is standard for concrete block. 4. Choose your wall material from the dropdown (concrete block, poured concrete, stone, or timber). 5. Enter the footing depth and footing width in inches — a common rule of thumb is footing depth equal to wall thickness and width equal to twice the wall thickness. 6. Optionally enter your estimated labor cost per square foot and material cost per square foot. 7. Click Calculate to see your results, including block count, footing concrete volume, and total estimated cost.
How the Retaining Wall Calculator Works
This calculator uses your wall dimensions to compute key material quantities and cost estimates for your retaining wall project. Below is an explanation of each calculation.
Wall Face Area
The wall face area is simply the length multiplied by the height: Area = Length × Height. This is used as the basis for material and labor cost estimates.
Block / Unit Count
For concrete block walls, a standard block covers approximately 0.44 sq ft of face area (8 in × 8 in nominal). The calculator divides total wall area by this face area and adds a 5% waste factor: Blocks = (Wall Area / 0.444) × 1.05. For other materials the same unit estimate applies as a rough guide.
Wall Material Volume
Wall volume is computed as: Volume = Length × Height × Thickness. This is useful for poured concrete walls where you need to order ready-mix concrete.
Footing Concrete
The footing is the underground foundation that supports the wall. Its volume is: Footing Volume = Length × Footing Width × Footing Depth. The result is also converted to cubic yards (divide by 27) since ready-mix concrete is sold by the cubic yard.
Cost Estimation
Material cost equals the wall face area multiplied by your material unit cost per square foot. Labor cost equals the wall face area multiplied by your labor rate per square foot. The total is the sum of both:
- Material Cost = Wall Area × Material Rate
- Labor Cost = Wall Area × Labor Rate
- Total Cost = Material Cost + Labor Cost
Design Considerations
Retaining walls taller than 4 feet typically require engineering review and building permits. Proper drainage behind the wall (gravel backfill and weep holes) is critical to prevent hydrostatic pressure buildup. Always check local building codes before starting construction.