Quick answer
Calculate each footing type separately. A continuous footing uses length × width × depth, while an isolated pad uses pad length × pad width × pad depth. Add all sections, then convert cubic feet to cubic yards.
Step by step
- List footing types Separate continuous walls, isolated pads and steps.
- Use designed dimensions Do not substitute excavation dimensions for concrete dimensions.
- Calculate each section Multiply length, width and depth in feet.
- Add and convert Total cubic feet ÷ 27 gives cubic yards before ordering rules.
Formula or rule of thumb
footing volume(ft³) = length × width × depth; yd³ = total ft³ ÷ 27
Example
A 60 ft strip footing 1.5 ft wide and 0.75 ft deep is 67.5 ft³, or 2.50 yd³.
Common mistakes
Confusing trench size with concrete size, ignoring steps, and estimating reinforcement from volume alone.
Planning note: product yields, installation methods, site conditions and local requirements can change the final quantity. Use the exact manufacturer or supplier information before purchasing.
FAQ
Are footing dimensions universal?
No. Soil, loads, frost depth and local rules control design.
Can I combine pads and strip footings?
Calculate them separately and add the volumes.
Does this design a foundation?
No. It is only a quantity estimate.