Retaining wall cost by height and material
Estimates from this calculator's default prices for a 30 ft straight wall with drainage stone, a drain pipe and filter fabric behind it. Your local prices will differ, so change the defaults above to match quotes or supplier prices near you.
| Wall, 30 ft long | Segmental block | Treated timber | Poured concrete |
|---|---|---|---|
| 2 ft high | $2,050–$3,050 | $2,300–$3,400 | $3,850–$5,800 |
| 3 ft high | $2,700–$4,050 | $2,950–$4,450 | $5,050–$7,600 |
| 4 ft high | $3,350–$5,050 | $3,600–$5,400 | $6,300–$9,450 |
Poured concrete figures are rougher: they use one per-square-foot material price, so replace it with a local quote if you have one.
Retaining wall cost per square foot
Per square foot of wall face above ground, a segmental block wall 30 ft long comes to about $42 at 2 ft high, $37 at 3 ft and $35 at 4 ft with these defaults. Per foot of wall that's about $84, $112 and $140. Short walls cost more per square foot because the trench, base, cap and drain pipe cost the same whatever the height, and one course of block is buried below grade.
How much does a 3 foot retaining wall cost?
A 3 ft block wall 30 ft long costs about $2,700–$4,050 installed here. It takes 170 wall blocks and 24 caps (seven courses, one of them buried), 2 tons of base gravel, 6 tons of drainage stone and 40 ft of drain pipe. Materials come to about $1,486. Labor is about 26 worker hours to dig the trench, compact the base, set the block and backfill. A 50 ft wall of the same height is about $4,400–$6,550, and 100 ft about $8,600–$12,900.
Concrete retaining wall cost
A poured concrete wall needs a footing, forms on both sides, rebar and ready-mix, and much more labor per square foot than stacking block. With these defaults a 30 ft concrete wall 3 ft high costs about $5,050–$7,600, or about $211 per foot. A 50 ft wall 4 ft high is about $10,400–$15,600. The default allows $15 per sq ft of face for concrete, rebar and form materials, counting 1 ft below grade, and 2 sq ft of face per worker hour.
Railroad tie and timber walls
Timber walls use 6×6 pressure-treated timbers stacked and pinned, with deadmen tied back into the slope. With $40 per 8 ft timber, a 30 ft wall 3 ft high comes to about $2,950–$4,450 here, close to block. Old railroad ties are treated with creosote, and many people avoid them near gardens. Wood also rots eventually.
When a wall needs an engineer
Walls over about 4 ft, or shorter walls holding back a slope, a driveway or a building, typically need an engineered design and a permit. Geogrid and design work aren't in this estimate. Enter any permit or engineering fee above, and check with your building department before you get quotes.
What changes the price
- Height: each 6 in of height adds a course of block and more drainage stone.
- Material: segmental block and timber cost about the same here. Poured concrete costs roughly twice as much.
- Drainage: leaving out the stone, pipe and fabric cuts a 3 ft block wall to about $2,350–$3,500, but water pressure behind a wall is the usual reason walls fail.
- Access and soil: rock, roots and tight access slow digging. Lower the build rate above for a hard site.
How this estimate works
Block walls follow our retaining wall calculator: 6×16 in face blocks at $5 with one course buried, 16 in caps at $5, 5% waste, a 24 in wide × 6 in deep crusher-run base at $38 a ton, 12 in of drainage stone behind the full height at $45 a ton, 4 in perforated pipe at $1.25 a foot, filter fabric, and $85 delivery. Timber walls use 5.5 in tall timbers with one course buried and 10% added for deadmen and waste. The contractor's markup on materials is 20%. Labor is the wall face, including the buried course, divided by a build rate of 4 sq ft per worker hour for block, 5 for timber and 2 for concrete, billed at $60 an hour including overhead and profit. The range is the result minus 20% to plus 20%. Homewyse puts a dry-stacked interlocking block wall up to 3 ft high at $35.41–$48.62 per sq ft nationally (May 2026); our default 30 ft block wall 3 ft high comes to about $37 per sq ft of face above ground at the middle of its range.
Getting quotes
Get at least three quotes for the same length, height and material. Ask about base depth, drainage, geogrid and who handles the permit. If a quote leaves out drainage, ask why.
Questions
How much does a retaining wall cost per square foot?
With this calculator's typical defaults, a segmental block wall 30 ft long costs about $35–$42 per sq ft of face above ground, depending on height. Poured concrete costs roughly twice as much. Local prices vary.
How much does a 3 foot retaining wall cost?
A 30 ft block wall 3 ft high comes to about $2,700–$4,050 installed with these defaults, or about $112 per foot of wall.
Do I need a permit for a retaining wall?
Many towns require a permit and an engineered design for walls over about 4 ft, or for any wall holding back a slope, driveway or building. Check with your building department.
Can I build a retaining wall myself?
Short block walls are a common DIY project. A 30 ft wall 3 ft high needs about $1,486 of materials in this estimate, against $2,700–$4,050 installed. The base and drainage matter more than the blocks.