What goes into the cost of a retaining wall
- Wall blocks, including the buried first course and waste.
- Cap blocks along the top, usually glued down with masonry adhesive.
- Gravel: a compacted base pad and a drainage zone of clean crushed stone behind the wall.
- Drain pipe: perforated pipe along the back of the base, run out to daylight.
- Labor: excavation, base preparation and laying, usually quoted per square foot of wall face.
In the US, the calculator pre-fills example prices to show how the estimate is built. They are not quotes: use your own. Elsewhere, enter prices in your own currency.
Example: a 20 ft retaining wall, 2 ft high
With standard 16 × 6 in face blocks, the wall has 4 exposed courses plus 1 buried course, so 5 courses of 15 blocks. That's 75 blocks, or 79 with 5% waste, plus 21 cap blocks. The drainage zone and base pad take about 2.9 yd³ of crushed stone, roughly 4 tons.
| Item | Quantity | Example price | Cost |
|---|---|---|---|
| Retaining wall blocks | 79 | $6 each | $474 |
| Cap blocks | 21 | $4 each | $84 |
| Crushed stone (base + drainage) | 3.99 tons | $45 per ton | $180 |
| Perforated drain pipe | 20 ft | $1 per ft | $20 |
| Labor | 40 ft² of face | $15 per ft² | $600 |
| Total | ≈ $1,358 (≈ $34 per ft² of face) |
The cost per square foot is based on the exposed wall face (length × height above ground). The buried course, base and drainage all add cost without adding visible wall, so short walls cost more per square foot than tall ones.
What makes a retaining wall cost more
- Height. Walls over about 3–4 ft (1–1.2 m) usually need geogrid layers, an engineered design and often a permit. That adds materials, excavation and fees.
- Block type. Large, heavy blocks and natural-stone looks cost more per block, but they cover more face per block.
- Access and soil. Machine access, rock, clay and hauling away the soil you dig out all affect labor.
- Curves, steps and corners need cutting and special corner blocks.
- Drainage. Filter fabric, extra stone and longer pipe runs on wet sites.
To count blocks and gravel without prices, use the retaining wall calculator.
Safety: walls that hold back a slope, driveway or building, and any wall over about 3–4 ft, should be designed by a qualified professional. This page gives material and cost estimates only.
Frequently asked questions
How much does a block retaining wall cost?
It depends on the block, the height, the site and local labor. With the example prices on this page, a 20 ft × 2 ft wall comes to about $1,360 including materials and labor, or about $34 per square foot of wall face. Get local quotes for a real price.
How do I calculate the cost of a retaining wall?
Count the blocks (courses × blocks per course, with one buried course), the caps and the gravel, and multiply each by its price. Then add labor per square foot of face. The calculator does each step for you.
How many retaining wall blocks do I need?
Divide the wall length by the block face length to get blocks per course. Multiply by the number of courses, which is the exposed height divided by the block height, plus at least one buried course. Add 5% for waste.
Is it cheaper to build a retaining wall yourself?
Labor is often half or more of the total, so building a short wall yourself can save a lot. Walls over about 3–4 ft, or walls holding up a driveway or building, need an engineered design and should be built by a professional.
Does the estimate include geogrid?
No. Geogrid reinforcement, filter fabric, excavation equipment, soil disposal and permits are not included. Add them if your wall needs them.