Retaining Wall Calculator
Estimate the blocks, caps and drainage gravel for a retaining wall, and see what the wall costs per square foot of face.
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Estimated cost
$795 – $1,317
Typical figure around $1,056.
- Wall face
- 90 sq ft
- Blocks
- 102 blocks
- Caps
- 45 caps
- Drainage gravel
- 5 tons
Stone and backfill drainage included. Walls over 4 ft usually need a permit or an engineer.
Planning estimate only — confirm quantities with your supplier or contractor before ordering.
How this estimate is calculated
The estimate is built from wall length (ft), wall height (ft) and wall material, then priced at national average rates. It reports wall face, blocks, caps and drainage gravel, with quantities rounded up so you are never short of material and the standard waste allowance already included where it applies.
Stone and backfill drainage included. Walls over 4 ft usually need a permit or an engineer.
The dollar range is a national average, so treat it as a starting point rather than a bid. Labor rates, permit fees and material delivery differ by region — the state table below shows how your state compares, and construction cost by state breaks the picture down further.
Prefer the longer version? Read our guide to How much does a gravel driveway cost.
Cost by wall material
Each row prices the same default job shown in the calculator above, changing only the wall material. Use it to see what the upgrade or the cheaper option really costs before you commit.
| Wall material | Low | High |
|---|---|---|
| Segmental concrete block | $795 | $1,317 |
| Timber landscape ties | $570 | $1,002 |
| Poured concrete | $2,010 | $3,477 |
| Natural stone boulder | $1,830 | $3,207 |
What the same job costs by state
Every row applies that state's construction cost index to the national range calculated above. The index bundles local labor rates, permit fees and material delivery, so it is a planning figure rather than a bid.
| State | Index | Low | High |
|---|---|---|---|
| Ohio | 0.92 | $731 | $1,211 |
| Texas | 0.93 | $739 | $1,225 |
| North Carolina | 0.94 | $747 | $1,238 |
| Georgia | 0.95 | $755 | $1,251 |
| Arizona | 1.01 | $803 | $1,330 |
| Florida | 1.02 | $811 | $1,343 |
| Pennsylvania | 1.03 | $819 | $1,356 |
| Illinois | 1.05 | $835 | $1,383 |
| Colorado | 1.08 | $859 | $1,422 |
| Washington | 1.15 | $914 | $1,514 |
| California | 1.32 | $1,049 | $1,738 |
| New York | 1.42 | $1,129 | $1,870 |
Index 1.00 is the national average. See construction cost by state for metro-level figures and the projects homeowners ask about most.
Where to buy materials
Links to suppliers are sponsored: if you buy through them, we may earn a commission at no extra cost to you. It never affects an estimate.
- Search The Home Depot“retaining wall block”
- Search Lowe's“retaining wall block”
Frequently asked questions
How thick should a retaining wall be?
A segmental block wall is usually one block wide up to about 3 ft, and two blocks wide with a geogrid tie-back above that. Poured walls should be engineered once the retained height passes 4 ft.
Do I need drainage behind a retaining wall?
Always. Water pressure is what destroys retaining walls, so backfill the upper half with clean gravel wrapped in filter fabric and run a perforated pipe to daylight at the base.
How much does a retaining wall cost per square foot?
Segmental concrete block runs about $6.50 to $11 per square foot of wall face, plus a gravel backfill allowance. Timber ties are cheaper at $4 to $7.50, while poured concrete and natural boulder are the most expensive at $18 to $35.
When does a retaining wall need a permit or an engineer?
Most jurisdictions require a permit once a wall retains more than 4 ft of soil, and often an engineer’s stamp above that. Terracing two shorter walls instead of building one tall one is a common way to stay under the threshold.
Does this cost change from state to state?
Yes. Applying each state's construction cost index to the national range of $795 to $1,317, the same job runs from about $731 to $1,211 in Ohio (index 0.92) to $1,129 to $1,870 in New York (index 1.42).
What is not included in this estimate?
Stone and backfill drainage included. Walls over 4 ft usually need a permit or an engineer. The figure is a national planning average for the work described above, not a contractor's quote.
