Estimate blocks, materials, and costs for your retaining wall project by length, height, and material type.
LotSite starting assumption
The prices filled in here are LotSite starting assumptions, not quotes and not sourced prices. Prices differ by region and supplier, so type in a local quote and the estimate will use it.
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Estimated cost for a 2-foot tall retaining wall by length and material.
Dollar figures here use LotSite starting assumptions, not quotes and not sourced prices. Use the calculator above with a local quote for your own number.
| Length | Concrete Block | Natural Stone | Timber / Railroad Tie | Interlocking Block |
|---|---|---|---|---|
| 20 ft | $300 | $700 | $360 | $440 |
| 30 ft | $450 | $1,050 | $540 | $660 |
| 50 ft | $750 | $1,750 | $900 | $1,100 |
| 75 ft | $1,125 | $2,625 | $1,350 | $1,650 |
| 100 ft | $1,500 | $3,500 | $1,800 | $2,200 |
| 150 ft | $2,250 | $5,250 | $2,700 | $3,300 |
Estimates are for a 2-foot tall wall with materials only. Taller walls cost proportionally more. Professional installation typically doubles the total.
Retaining walls hold back soil on sloped properties, preventing erosion and creating level terraces for gardens, patios, and lawns. They are one of the most impactful landscaping features you can add. Both functionally and aesthetically.
For DIY projects, concrete interlocking blocks are the most beginner-friendly option. They stack without mortar and are designed to lean back slightly into the slope for stability. For walls under 3 feet, a homeowner with basic tools can build one in a weekend.
The most important part of any retaining wall is drainage. Water pressure behind a wall is the number one cause of failure. Always install a perforated drain pipe at the base and backfill with gravel. Never backfill directly with soil.
The cost figure takes the per-foot price for a 2-foot wall and scales it in proportion to the height you enter, so a 4-foot wall is priced at twice the 2-foot rate. Real walls do not scale that neatly. Taller walls use larger blocks, more courses, a wider base, and geogrid reinforcement, so the cost per foot rises faster than the height. Treat the figure for anything over 3 feet as a floor rather than an estimate.
The block count divides the face area by 0.89 square feet per block, which is the face of a 16 by 8 inch unit, and adds 5 percent for cuts. Many landscape retaining blocks have a 12 by 4 inch face, 0.33 square feet, so a wall built from those needs almost three times the count shown. Check the face size of the block you are buying. The height you enter should also include the buried first course, since those blocks are bought too.
Backfill gravel assumes a 12-inch wide drainage zone behind the full height of the wall. It leaves out the base: manufacturer installation guides call for a compacted gravel trench under the first course, 6 inches deep and wider than the block, plus the perforated drain pipe and filter fabric. Cap blocks, construction adhesive for the caps, and geogrid for walls over about 3 feet are not counted either.
The number is most wrong where the height changes along the wall, on a slope that runs with it, or where the wall holds back a driveway or sits below a structure, which needs engineering regardless of height. For a stepped wall, enter the average height, or run the calculator once per segment and add the results.
Enter your address to view your property slope and plan your retaining wall location.
Also check out our gravel calculator and fence calculator