How Much Concrete for a Foundation Wall?

How much concrete for a foundation wall is a straightforward volume calculation: length times height times thickness, all in feet, divided by 27 to get cubic yards. An 8-inch-thick wall that is 8 feet tall uses about 0.2 cubic yards per linear foot, so a 100-foot perimeter needs roughly 20 yards before waste. Footings are calculated separately. Here is the math, a quick reference table, and what to add for waste.

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The formula

Measure total wall length in feet around the foundation.
Multiply by wall height in feet.
Multiply by wall thickness in feet (8 inches is 0.667 feet, 10 inches is 0.833 feet, 12 inches is 1 foot).
Divide by 27 to convert cubic feet to cubic yards.
Add 5 to 10 percent for waste, form bulging, and uneven footings.

Example: 120 feet x 8 feet x 0.667 feet = 640 cubic feet. 640 ÷ 27 = 23.7 cubic yards. With 8 percent extra, order about 25.6 yards.

Yards per linear foot

Wall height	8-inch wall	10-inch wall	12-inch wall
4 feet	About 0.10 yd/ft	About 0.12 yd/ft	About 0.15 yd/ft
8 feet	About 0.20 yd/ft	About 0.25 yd/ft	About 0.30 yd/ft
9 feet	About 0.22 yd/ft	About 0.28 yd/ft	About 0.33 yd/ft
10 feet	About 0.25 yd/ft	About 0.31 yd/ft	About 0.37 yd/ft

Multiply by the perimeter in feet for a fast estimate, then add your waste factor.

Sample foundations

Foundation	Perimeter	Wall	Approximate yards (no waste)
24 x 24 garage stem wall, 4 ft	96 ft	8 in	About 9.5
28 x 40 basement, 8 ft	136 ft	8 in	About 26.9
30 x 50 basement, 9 ft	160 ft	10 in	About 44.4

Deduct openings

Subtract windows, doors, and large blockouts if they are significant. For each opening, multiply its width by height by wall thickness, divide by 27, and subtract. Small pipe sleeves do not matter.

Don’t forget footings

Walls sit on footings, which are poured separately and often calculated the same way: length times width times depth. A common residential footing might be about 16 to 24 inches wide and 8 to 12 inches deep, but sizes depend on local code, soil, and loads.

Ordering and placing

Wall pours are usually pumped or placed with a chute from a truck positioned around the foundation. See concrete pump truck cost.
Ask for a wall mix with suitable slump and strength for your plans.
Schedule trucks carefully; large walls may need several truckloads. See yards in a concrete truck.
Have extra on call rather than running short mid-pour.

Bottom line

To figure how much concrete for a foundation wall, multiply perimeter, height, and thickness in feet, divide by 27, and add 5 to 10 percent. An 8-inch wall 8 feet tall takes about 0.2 yards per linear foot. Calculate footings separately and follow your plans and local code. Run your numbers through the concrete calculator.

Questions people ask

How many yards of concrete for a basement wall?

An 8-inch wall 8 feet tall needs about 0.2 cubic yards per linear foot. Multiply by the perimeter and add waste.

How thick are poured foundation walls?

Many residential walls are 8 or 10 inches thick, depending on height, soil, and local code.

Should I add extra concrete for a wall pour?

Yes. Add about 5 to 10 percent for waste, form bulging, and uneven footings.

Do I subtract windows from a wall calculation?

Subtract large openings like windows and doors. Small pipe sleeves can be ignored.

Are footings included in wall calculations?

No. Calculate footings separately using length, width, and depth.

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