A Footing Volume Calculator is a crucial tool for construction projects that determines the precise amount of concrete needed for a building's foundation footings. Footings are the wide bases at the bottom of foundation walls that spread the building's load over a larger area of soil. This calculator takes the dimensions of a footing—its length, width, and depth—and computes the total volume of material required. For projects with multiple identical footings, it quickly calculates the grand total. Consequently, this tool is essential for accurate material ordering, project budgeting, and minimizing waste. Using it ensures you purchase the right amount of concrete, preventing costly shortages or expensive overages.
formula of Footing Volume Calculator
You can calculate the volume of concrete needed for footings using these standard geometric formulas. Ensure all your measurements use the same unit (e.g., all feet or all meters) before you begin.
- Rectangular Footing Volume Formula:
Footing Volume (V) = Length × Width × Depth
Where:
Length = Footing length (in meters, feet, etc.)
Width = Footing width (same unit)
Depth = Footing thickness or height (same unit)
V = Volume (in cubic meters or cubic feet)
- For Multiple Footings:
Total Volume = Number of Footings × Volume of One Footing - Circular Footing Volume:
Volume (V) = π × (Diameter / 2)² × Depth
Unit Conversion (if needed):
1 cubic meter = 1,000 liters
1 cubic foot ≈ 0.0283 cubic meters
1 cubic yard = 27 cubic feet
Concrete Volume for Common Rectangular Footing Sizes
To help you with quick estimations, this table shows the required concrete volume for various standard rectangular footing sizes. Concrete is typically ordered in cubic yards, so this conversion is included for practical use.
| Footing Dimensions (L x W x D) in Feet | Volume per Footing (Cubic Feet) | Volume per Footing (Cubic Yards) |
| 2 ft x 2 ft x 1 ft | 4.0 | 0.15 |
| 3 ft x 3 ft x 1 ft | 9.0 | 0.33 |
| 4 ft x 4 ft x 1 ft | 16.0 | 0.59 |
| 4 ft x 4 ft x 1.5 ft | 24.0 | 0.89 |
| 5 ft x 5 ft x 1 ft | 25.0 | 0.93 |
| 5 ft x 5 ft x 1.5 ft | 37.5 | 1.39 |
Example of Footing Volume Calculator
Let’s review an example for a backyard deck project. The plan requires 6 rectangular concrete footings to support the posts.
First, we define the dimensions for a single footing.
Length: 2 feet
Width: 2 feet
Depth: 1.5 feet
Next, we calculate the volume of one footing using the formula.
Footing Volume (V) = Length × Width × Depth
Footing Volume (V) = 2 ft × 2 ft × 1.5 ft = 6 cubic feet
Now, since the project requires 6 identical footings, we calculate the total volume.
Total Volume = Number of Footings × Volume of One Footing
Total Volume = 6 × 6 cubic feet = 36 cubic feet
Finally, since concrete suppliers sell by the cubic yard, we convert the total volume.
Total Volume in Cubic Yards = Total Cubic Feet / 27
Total Volume in Cubic Yards = 36 / 27 = 1.33 cubic yards
Therefore, you would need to order at least 1.33 cubic yards of concrete for the project.
Most Common FAQs
Always order 5-10% extra concrete to account for spillage, uneven ground, and material left in the mixer. This "waste factor" prevents a project-delaying shortage. Having a little extra is much better than running out.
Yes, this is essential. All measurements (length, width, depth) must be in the same unit, like feet or meters, before multiplying. Using mixed units will cause an incorrect volume calculation and a wrong material order.
Footings are thick strips of concrete that support foundation walls and posts, spreading the structural load. A slab is a large, flat concrete surface that serves as a floor, like in a basement or garage. Footings support concentrated loads, while slabs cover large areas.