Charge $20 to $35 per square foot of wall face for segmental block, $15 to $30 for timber and $20 to $45 for poured concrete. Those are HomeGuide's installed ranges, and they describe the part of the wall the customer can see. The money you lose is behind it. A block wall 40 feet long and 3 feet tall comes to $2,600 to $4,550 at those rates. Cut into a bank and built to Allan Block's install guide, the same wall has about 10 cubic yards of dirt to dig and haul. HomeGuide prices dig-out and disposal at $130 to $230 a yard. That is $1,365 to $2,415 of work on a wall you may have quoted at $2,600. Write the dirt as its own line.
What should you charge per square foot of retaining wall?
Between $15 and $52 depending on the wall type and on whose number you trust. The published ranges do not agree, and the gap between them is the lesson.
| Wall type | Installed price per face sq ft | Source |
|---|---|---|
| Timber | $15-$30 | HomeGuide |
| Segmental or CMU block | $20-$35 | HomeGuide, concrete walls |
| Poured concrete | $20-$45 | HomeGuide |
| Block, itemized calculator | $37.55-$51.76 | Homewyse, September 2026 |
| All walls, average | $35-$65 | HomeGuide |
Homewyse's low end sits above HomeGuide's high end for the same block. Read the Homewyse scope and you see why the bottom of the other range is thin. It assumes "favorable site conditions," digging no more than a foot below grade, and a wall no taller than 8 courses. It leaves out the permit. Then it tells the reader to add 13% to 22% if a general contractor runs the job.
So even the higher number is a wall on flat ground with a truck parked next to it. I would treat $20 a foot as the price of a garden border with nothing behind it, and start a real wall, one with stone and a drain, near $38.
Measure the face from the bottom of the buried course to the top of the cap. Allan Block calls for an inch of buried block for every foot of wall height. On the 40-foot wall that is 3 inches the customer never sees and 10 square feet you laid.
What should you charge per linear foot?
Multiply your face rate by the height. Customers ask for a per-foot price because it sounds simple, and it is only simple if the height never changes.
| Wall height | Block at $20-$35 per sq ft | What changes |
|---|---|---|
| 2 ft | $40-$70 per LF | Often under your minimum |
| 3 ft | $60-$105 per LF | Gravity wall, no plans |
| 4 ft | $80-$140 per LF | Permit line in most towns |
| 6 ft | $120-$210 per LF | Engineer, geogrid, a much bigger dig |
HomeGuide's own calculator scales in a straight line, with a 6-foot wall priced at exactly three times a 2-foot wall. No wall works that way. The extra cost past 4 feet is not in the block. It is the engineer and the hole.
A short wall has the opposite problem. Twenty feet of 2-foot wall is $800 to $1,400 at these rates, and HomeGuide says most wall contractors carry a $1,500 to $3,000 project minimum. Quote the minimum.
What goes in the ground that the face price does not show?
Stone, and a lot of missing dirt. Take the 40-foot wall, 3 feet exposed, cut into a slope. Allan Block's guide gives you the quantities:
- Base trench. 18 inches wide for a wall under 4 feet, with at least 6 inches of compacted wall rock, plus the 3 inches of buried block. About 30 cubic feet of stone.
- Stone behind the wall. 12 inches of wall rock behind the block, to the full height. About 130 cubic feet, before you fill the cores.
- The cut. A foot of block and a foot of stone means the bank comes back 2 feet along the whole wall. With the trench, that is roughly 285 cubic feet of soil. Call it 10.5 yards, and it swells once it is in the truck.
That is 6 yards of clean stone. At roughly 1.4 tons to the yard it is a bit over 8 tons, and your quarry will give you the real conversion for what they sell.
| Line | Quantity | Published price | On this wall |
|---|---|---|---|
| Wall face, block | 130 sq ft | $20-$35 per sq ft | $2,600-$4,550 |
| Dig and haul | 10.5 cu yd | $130-$230 per cu yd | $1,365-$2,415 |
| Drain pipe to daylight | 40 LF | $10-$30 per LF | $400-$1,200 |
| Wall rock, delivered | 6 cu yd | Your quarry's price | - |
Some of that digging is already inside a published face rate. Homewyse includes the first foot. None of them include the bank. Know which yards your square-foot number covers, and bill the rest.
Two things from the field. The dirt you dug out does not go back behind the wall. Allan Block says organic soil cannot be used as backfill, and clay holds water against the block. The second is the gate. Eight tons of stone through a 36-inch side gate is a day with a wheelbarrow, and no per-foot rate has that day in it. HomeGuide puts hard digging in rocky or clay soil at up to 50% more labor. Bad access belongs in the same conversation.
Allan Block only requires the drain pipe on reinforced walls, gravity walls over 4 feet and wet sites. Put it in anyway. The wall that leans in year three is almost always the one holding water.
When does a retaining wall need a permit and an engineer?
Over 4 feet, in most places, and sooner than that if anything sits on top. The International Residential Code, R105.2, exempts retaining walls "not over 4 feet" measured "from the bottom of the footing to the top of the wall, unless supporting a surcharge."
Two phrases in that sentence cost contractors money.
Bottom of the footing. Not the grade. A wall showing 3 feet 9 inches with a buried course under it can be over the line. Ask your building department how they measure a block wall before you promise the customer there is no permit.
Surcharge. A driveway above the wall counts. So does a slope running up from the cap. Either one removes the exemption at any height. A 3-foot wall holding up the edge of a parking pad is an engineered wall.
HomeGuide puts the permit at $50 to $450 and the engineer at $500 to $2,000 or more. Pass both through as their own lines with your markup, the way you would any sub. The reasoning is in marking up subcontractors.
Then price what the plans add. Allan Block's guide says to excavate behind the wall "to accommodate the design length of the geogrid," so the dig grows faster than the wall does. Geogrid comes in 50-foot rolls. If the plans call for three layers on a 40-foot wall, that is 120 feet. Three rolls.
What do you say when the customer wants the low-cost wall?
Change the face. Leave the ground alone. Timber at $15 to $30 a square foot is a fair answer to a tight budget, as long as the customer hears the other number too: HomeGuide gives wood 10 to 40 years and concrete 50 to 100.
What you do not do is get to the low price by skipping the stone or the pipe. Nobody can see either one on the day you get paid. Everybody can see the bulge three winters later, and it has your name on it.
If the budget still does not reach, shorten the wall or step it into two low ones. Do not thin the base. And if the job is a rebuild, add HomeGuide's $15 to $30 a linear foot for demolition, then go find out why the old wall failed. Usually a downspout empties behind it. That is a line for the estimate too, or an exclusion in writing. There is more on writing those in what to exclude from a contractor estimate.
What this misses
The ranges are national. None of these sources price by metro, and what a yard of dirt costs to dump in Seattle is not what it costs in Des Moines.
The stone has no published price here. Delivered wall rock varies too much by quarry distance to quote a national figure. Get it by the ton from your yard before you send the number.
The 4-foot rule is the model code. Your town may have amended it. HomeGuide notes that some cities start at 3 feet.
Poured walls are a different trade. Forms, rebar and a footing below frost are priced like flatwork with height, and pricing concrete by the square foot is the closer guide.
Soil. Everything above assumes ground that holds a trench. Old fill and wet ground are engineer questions at any height.
BidWalk writes the wall face, the dig, the stone and the drain as separate lines while you walk the slope and call out the length and height.
