What is a Poured Concrete Wall?
A poured concrete wall is exactly what it sounds like: a continuous, solid wall formed by pouring wet concrete into temporary wooden or metal forms. Once the concrete cures and the forms are stripped away, you are left with an incredibly strong, monolithic structure.
Poured concrete walls are most commonly used for basement foundations, retaining walls to hold back soil, and increasingly in above-grade residential construction (ICF or Insulated Concrete Forms) due to their superior strength, fire resistance, and soundproofing qualities.
How to Calculate Concrete Volume for Walls
Because poured walls require a massive amount of concrete, knowing exactly how much to order is critical. Walls are calculated as rectangular prisms. You need the length, the height, and the thickness.
The Formula
To find the volume of a poured wall in cubic yards:
- Convert the Thickness from inches to feet by dividing by 12.
- Multiply the Length (ft) × Height (ft) × Thickness (ft) to get the total Cubic Feet.
- Divide the total cubic feet by 27 to convert to Cubic Yards.
Volume (yd³) = (Length × Height × (Thickness ÷ 12)) ÷ 27
Example Calculation
Imagine you are pouring a foundation wall that is 40 feet long, 8 feet high, and 8 inches thick.
- Convert thickness to feet:
8 in ÷ 12 = 0.667 ft - Calculate cubic feet:
40 ft × 8 ft × 0.667 ft = 213.44 cubic feet - Convert to cubic yards:
213.44 ft³ ÷ 27 = 7.90 cubic yards
If you are pouring a full basement with four walls, you would calculate the volume of each wall segment and add them together.
The Importance of Wall Forms
Unlike pouring a slab on the ground, pouring a wall means fighting gravity. Wet concrete exerts tremendous lateral (sideways) pressure on the forms holding it.
If the forms are not properly tied and braced, they can "blow out"—meaning the form bursts open and thousands of pounds of wet concrete spill onto the ground. This is an extremely expensive and dangerous disaster. Professional formwork is highly engineered to withstand this hydrostatic pressure.
Accounting for Openings (Windows and Doors)
Our calculator determines the total solid volume of the wall. If your foundation wall will have large basement windows or walk-out doors, those openings displace concrete.
To be extremely precise, you can calculate the volume of those openings (Length × Height × Thickness) and subtract them from your total. However, many contractors simply ignore small window openings and use that displaced concrete as their built-in "waste factor" to ensure they don't run short during the pour.