Concrete Wall Calculator
Calculate concrete for walls and retaining walls. Enter length, height and thickness to get cubic yards, cubic feet and bag count.
Wall Dimensions
Concrete Required
How to Calculate Concrete for a Wall
Calculating the volume of concrete for a poured wall is straightforward. Since a wall is essentially a vertical rectangular slab, the math is exactly the same as pouring a driveway or a floor slab. You multiply the length, height, and thickness together.
Make sure to convert the thickness of the wall from inches into feet before multiplying. Once you have the total cubic feet, divide by 27 to find the required cubic yards. When pouring vertical forms, always order an extra 5% to 10% to account for spillage, pumping waste, and form bulging.
Wall Calculation Formula
Cubic Yards = (Length × Height × (Thickness ÷ 12)) ÷ 27
Example for a 20ft long wall, 6ft high, 8 inches thick: (20 × 6 × 0.66) ÷ 27 = 2.96 cubic yards.
Frequently Asked Questions
How many yards of concrete for a retaining wall?
The amount depends on the dimensions. For example, a retaining wall 20 feet long, 4 feet high, and 8 inches thick requires 1.98 cubic yards of concrete (plus waste).
How thick should a concrete wall be?
A standard residential foundation wall is typically 8 inches thick. Retaining walls can range from 8 to 12 inches thick depending on the height and the soil pressure it needs to retain.
How many bags of concrete for a wall?
For every cubic yard of wall volume, you will need approximately forty-five 80lb bags of concrete. Poured walls usually require ready-mix delivery due to the large volume needed.
How do you calculate concrete for a block wall?
If you are building a CMU block wall, you need mortar for the joints and fill concrete for the cores. You can use our Concrete Block Calculator to find exact core fill requirements.