Concrete Wall Calculator
This concrete wall calculator estimates the concrete for a poured wall or foundation wall from its length, height, and thickness. It returns cubic yards, cubic feet, weight, and bag counts, so you can order ready-mix for a basement, retaining, or stem wall with confidence. It works equally well as a poured wall concrete calculator for any vertical pour.
How to use this calculator
- Enter the wall length and height.
- Set the thickness — residential foundation walls are usually 8–10 inches.
- Add a waste allowance.
- For large door or window openings, subtract their volume separately.
The formula
A wall is a tall, thin box: length × height × thickness. Keep the units in feet and divide by 27 for cubic yards:
Cubic yards = (Length ft × Height ft × Thickness ft) ÷ 27
Worked example. A 20 ft long, 8 ft tall wall that is 8 inches thick: 8 inches is 0.667 ft, so 20 × 8 × 0.667 = 106.7 cubic feet, which is 3.95 cubic yards. Add 10% waste and order about 4.35 cubic yards.
Frequently asked questions
How do I calculate concrete for a wall?
Multiply the wall length × height × thickness, keeping every measurement in feet, then divide by 27 for cubic yards. Thickness is usually entered in inches and converted automatically.
How much concrete for a foundation wall?
A 20 ft long, 8 ft tall, 8 inch thick wall holds about 3.95 cubic yards. Footings beneath the wall are calculated separately.
How thick are poured concrete walls?
Residential foundation walls are typically 8 to 10 inches thick. Taller walls or those holding back soil may need more thickness and extra reinforcement.
Should I subtract window and door openings?
For large openings, yes — calculate each opening’s volume and subtract it so you do not over-order. Small openings are often left in as a built-in safety margin.