Retaining Wall Material Calculator
Calculate concrete blocks, gravel backfill, and drainage materials needed for a retaining wall.
🏗️ Construction📐 Blocks = Wall Area / Block Face Area
Wall length (feet)
Wall height (feet)
Block face area (sq ft)
Gravel backfill depth (feet)
Please enter valid values.
Formula & Reference
| Variable | Formula | Units |
|---|---|---|
| Retaining Wall Material Calculator | Blocks = Wall Area / Block Face Area | blocks / tons |
Step-by-Step Examples
Example 1
Standard Retaining Wall
40 ft long, 4 ft high, standard blocks 0.67 sq ft.
- Wall area: 160 sq ft | Blocks: ceil(160/0.67 × 1.1) = 263
- Gravel backfill: 3.0 cu yd | Drainage: 5 pipes
✓ 263 blocks / 3 cu yd gravel
Example 2
Short Garden Wall
20 ft long, 2 ft high.
- Area: 40 sq ft | Blocks: ~66 | Gravel: ~0.74 cu yd
✓ ~66 blocks
Example 3
Tall Retaining Wall
60 ft long, 6 ft high.
- For walls over 4 ft: engineering required!
- Area: 360 sq ft | Blocks: ~590
✓ Engineering required for 6 ft+
Real-World Applications
Contractors
Calculate retaining wall materials for any job.
Homeowners
DIY retaining wall material estimates.
Estimators
Quick material takeoff for bidding.
Landscapers
Calculate retaining wall blocks for landscaping projects.
Common Mistakes to Avoid
⚠️
Building walls over 4 feet without engineering
Walls over 4 feet require engineering in most jurisdictions. Hydrostatic pressure and lateral earth pressure can collapse under-designed walls.
⚠️
Not providing drainage
Water trapped behind a retaining wall creates enormous hydrostatic pressure. Install drainage pipe and gravel backfill to prevent failure.
Frequently Asked Questions
What type of retaining wall block? ▾
Allan Block, Versa-Lok, and Keystone are popular systems with engineered design tables. Each has different block weights and face areas.
When is a permit required? ▾
Most jurisdictions require permits for walls over 3-4 feet. Always check local requirements before building.
What is a deadman? ▾
A horizontal anchor block that extends back into the hillside and is connected to the wall face. Required for taller walls to provide lateral stability.