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Retaining Wall Cost
See what a block retaining wall typically costs installed, then size yours to find how many blocks it needs. The calculator opens with 12 × 4 inch segmental blocks; change the block size to match your product. Want local pros to quote it? Use the quote form below the results.
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Estimate only. Bag yields, material density and waste vary by product and supplier. Confirm quantities with your supplier and check local building codes before you buy or build.
How much does a retaining wall cost?
Published 2026 cost guides put an installed concrete block or segmental retaining wall at roughly $15 to $35 per square foot of wall face, with taller or engineered walls and difficult sites higher. A 30 ft long wall that is 3 ft high (90 sq ft) is therefore about $1,350 to $3,150, and a 4 ft high wall works out to about $60 to $140 per linear foot. The blocks are only part of the price: excavation, a compacted gravel base, drainage pipe and backfill, geogrid on taller walls, and labor make up most of it.
What changes the price of a retaining wall
Height and length, the type of block or stone, how much has to be dug out, the base and drainage (drain pipe, gravel backfill, filter fabric), geogrid reinforcement, access for equipment, the soil behind the wall, and local labor rates. Cost rises quickly with height, because taller walls need more block, a deeper base and often engineering.
Height, permits and engineering
Many areas require a permit or an engineer's design for walls above about 4 feet, or for walls that hold up a driveway, a building or a slope. Rules vary, so check with your local building department before you plan or build, and ask a contractor what your soil and drainage need.
Material cost: how many blocks
A 30 × 3 ft wall is 90 square feet. With 12 × 4 inch segmental blocks that is 270 blocks, and about 297 with 10% for breakage and cuts. Use your product's actual face size in the calculator. Segmental retaining blocks are dry-stacked, so ignore the mortar line in the results; reinforced masonry (CMU) walls use mortar, rebar and grout instead.
Doing it yourself vs hiring a pro
A low garden wall is a reasonable weekend job. A wall that holds back real soil needs a proper base, drainage and sometimes geogrid, and mistakes show up years later as bulging or collapse. Use the quote form below the results to send your wall size to up to two local contractors, and compare what each includes: excavation, base, drainage, backfill and haul-away.
About these numbers
The installed price ranges summarize published cost guides checked in October 2026 and vary widely by region, height and site. The calculator counts blocks only; your local quotes decide the real cost.
Frequently asked questions
How much does a retaining wall cost per square foot?
About $15 to $35 per square foot of wall face installed in most guides for block or segmental walls, more for tall, engineered or difficult-access walls. Prices vary by region.
How much does a retaining wall cost per linear foot?
For a 4 ft high block wall, roughly $60 to $140 per linear foot, based on $15 to $35 per square foot of face. A taller wall costs more per foot of length.
How many blocks do I need for a retaining wall?
Divide the wall area (length × height) by the face area of one block, then add about 10% for waste. A 30 × 3 ft wall with 12 × 4 inch blocks needs about 297. Enter your own wall and block size above.
Do I need a permit for a retaining wall?
Often for walls above about 4 feet or walls that support a driveway, structure or slope, but rules vary. Check with your local building department before you build.
Is a retaining wall cheaper if I build it myself?
You save the labor, which is most of the cost, but a wall holding back soil needs a compacted base, drainage and correct backfill. Poorly built walls fail, so for anything tall or load-bearing, get a pro's quote.
How accurate is this estimate?
It is a planning estimate, not an order. Bag yields, material density and waste vary by product, supplier and job, so confirm quantities with your supplier and check local building codes before you buy or pour.
Are my measurements saved?
No. Everything is calculated in your browser. Nothing is uploaded or stored.
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Also on this topic: Concrete block calculator.