The average retaining wall cost is about $6,300, with most projects between $3,500 and $9,400. Priced by the face area of the wall, expect roughly $20–$53 per square foot, averaging about $33. Material, height, drainage and whether the wall needs engineering set the price.
Retaining wall cost per square foot by material
| Material | Approx. cost per sq ft of wall face | Typical use |
|---|---|---|
| Gabion (wire baskets of stone) | $10–$40 | Slopes, drainage-friendly walls |
| Timber / wood | $13–$35 | Short garden walls; shortest lifespan |
| Railroad ties | $18–$25 | Rustic landscaping (check local restrictions on treated ties) |
| Interlocking concrete block | $15–$35 | Most common DIY and pro option |
| Cinder block (CMU) | $15–$40 | Often faced with stucco or stone |
| Landscape block | $15–$60 | Decorative segmental walls |
| Brick | $17–$43 | Traditional look |
| Poured concrete | $20–$40 | Taller and structural walls |
| Natural stone | $20–$90 | Dry-stack or mortared stone |
To find face area, multiply wall length by exposed height. A 40-ft wall that's 3 ft tall has 120 sq ft of face. At $20–$53 per sq ft, that's roughly $2,400–$6,360.
Why height drives retaining wall cost
Taller walls hold back far more soil pressure, so cost rises faster than height alone suggests:
- Reinforcement: walls over about 4 ft, and concrete walls, typically need steel rebar, adding about $1.50–$2.50 per sq ft
- Geogrid: segmental block walls above a few feet often need geogrid layers extending into the backfill
- Footings: taller walls need deeper and wider bases
- Engineering: permits are usually required above 4 ft, and DIY walls over 3 ft should have a structural engineer
Many municipalities set their own height limits for permits and engineering. Check before you design, and always ask about walls near property lines, driveways or structures.
Drainage: the hidden essential
Water pressure behind a wall is a major cause of retaining wall failure. A well-built wall includes:
- Free-draining gravel directly behind the wall
- A perforated drain pipe at the base, leading to an outlet
- Filter fabric to keep soil from clogging the gravel
- Weep holes in solid walls
If your site already has water problems, pair the wall with a drain. See French drain cost.
Other retaining wall costs
| Item | Typical cost |
|---|---|
| Excavation | $50–$200 per cubic yard |
| Grading | at least about $500 |
| Leveling | $0.40–$2 per sq ft |
| Waterproofing (solid walls) | $2–$10 per sq ft |
| Land clearing | $735–$2,330 per acre |
| Permits | about $40–$450 |
By location, per-linear-foot ranges run about $30–$150 for landscape walls, $38–$138 along driveways and $108–$288 on shorelines.
How to estimate materials
For a segmental block wall:
- Courses: wall height ÷ block height, plus one buried base course
- Blocks per course: wall length ÷ block length
- Total blocks: courses × blocks per course, plus 5% waste
- Cap units: wall length ÷ cap length
- Base gravel and drainage stone: trench and backfill volumes in cubic yards
Our Retaining Wall Calculator counts blocks, caps and gravel. Use the Topsoil Calculator for backfill and planting soil.
Choosing the right wall
- Under about 3 ft, garden beds: interlocking block, timber or stone
- 3–4 ft: engineered block with geogrid, or poured concrete. Check permit rules.
- Over 4 ft or near structures: engineered design, permits and an experienced contractor
- Slopes with water: gabions or block with strong drainage
Terracing with two shorter walls instead of one tall wall can sometimes avoid engineering thresholds and look better. It needs more horizontal space. Building a raised patio? See paver patio cost.
Frequently asked questions
How much does a 50-foot retaining wall cost?
It depends on height. At 3 ft tall (150 sq ft of face) and $20–$53 per sq ft, roughly $3,000–$7,950.
What is the cheapest retaining wall?
Timber and some gabion walls have the lowest material cost, but timber has the shortest lifespan. Interlocking concrete block is a common value choice.
Do I need a permit for a retaining wall?
Often for walls taller than about 4 ft, and sometimes for shorter walls. Rules vary by municipality.
How long does a retaining wall last?
It depends on material, drainage and construction quality. Concrete, block and stone walls with good drainage last much longer than timber.
National averages for planning only. Structural walls need professional design.
