Retaining Wall Calculator
A retaining wall calculator estimates cast-in-place concrete for a rectangular stem and footing. Enter the dimensions from the wall section to get each volume, total cubic yards, and estimated weight. This calculator measures the section you provide; it does not size or check the wall design.
Concrete including allowance
38.89CY
- Stem before allowance
- 22.22 CY
- Footing before allowance
- 14.81 CY
- Weight including allowance
- 78.8 tons
Formula: CY = [L × H × (stem in ÷ 12) + L × footing W × (footing in ÷ 12)] ÷ 27, then + waste %
Uses a generic density from the site’s material table. Confirm a product-specific value with the supplier.
How the calculation works
Stem volume is wall length × stem height × stem thickness. Footing volume is wall length × footing width × footing thickness. Convert inch dimensions to feet before multiplying, then divide each cubic-foot volume by 27.
For a 100-foot wall with a 6-foot-high, 12-inch-thick stem and a 4-foot-wide, 12-inch-thick footing, the stem is 22.22 cubic yards and the footing is 14.81. The combined volume is 37.04 cubic yards before allowance, or 38.89 with an example 5% allowance.
Stem and footing results remain before allowance. Total concrete and weight include it. Weight uses the generic normal-weight concrete value of 150 lb/ft³; it is an estimate of material weight, not a lifting or structural check.
Enter stem height above the footing to avoid counting the intersection twice. Split tapered, stepped, or changing sections into separate calculations. Keys, reinforcement, drains, formwork, and backfill are separate quantities and are not included automatically.
Reference values
| Quantity | Value | Basis |
|---|---|---|
| Normal weight concrete | 150 lb/ft³ | generic unit weight |
| Weight per cubic yard | 4,050 lb ≈ 2.03 tons | 150 × 27 |
| Stem volume | L × H × t | prism |
| Footing volume | L × W × t | prism |
Frequently asked questions
Can I calculate only the stem?
Yes. Set footing width to zero.
Does the stem height include the footing?
Use the stem height above the footing for this two-prism model. Including the footing thickness again would count the overlap twice.
Can this calculate a tapered wall?
The widget assumes a constant rectangular section. Use an appropriate cross-sectional calculation separately for a taper or split the wall into sections.
Is this a wall design calculator?
No. It estimates quantities from dimensions you provide and does not determine reinforcement, bearing, stability, or drainage requirements.