How much concrete for a footing?
A footing estimate uses total run length, footing width, and footing depth. Convert width and depth into feet, multiply the dimensions, divide by 27, then add waste. For example, a 40 ft run that is 16 inches wide and 8 inches deep is about 1.32 cubic yards before waste, or about 1.45 cubic yards with 10% waste.
Common footing dimensions for planning
Common residential planning examples include 12 in wide x 6 in deep for light frame walls, 16 in wide x 8 in deep for many 8 in block wall examples, and 20 in wide x 10 in deep for heavier wall examples. These are quantity examples only. Required footing size, frost depth, reinforcement, and bearing details must come from local code, plans, soil conditions, or qualified guidance.
Concrete footing calculation example
For a 30 x 40 ft house foundation perimeter, the total run is 140 linear feet. Using a 16 in wide x 8 in deep footing with 10% waste: cubic yards = (140 x 1.33 x 0.67) / 27 x 1.10, which is about 5.07 cubic yards. A ready-mix order might be discussed around 5.25 cubic yards depending on supplier rounding.
Concrete footing cost per linear foot
Using a broad ready-mix material reference of $125-$165 per cubic yard, concrete material for a 16 in x 8 in footing is about $4.10-$5.45 per linear foot before waste. A 12 in x 6 in footing is about $2.30-$3.05 per linear foot, while a 24 in x 12 in footing is about $9.25-$12.25 per linear foot before waste. Labor, forms, excavation, rebar, inspection, delivery fees, and local pricing are separate.
Common footing dimensions for quantity planning
These examples are for material estimating only. Required footing size depends on plans, soil, loads, frost depth, and local code.
| Footing example | Planning dimensions | Concrete per 10 linear ft |
|---|---|---|
| Light frame wall example | 12 in wide x 6 in deep | 0.19 cu yd |
| 8 in block wall example | 16 in wide x 8 in deep | 0.33 cu yd |
| Heavier wall example | 20 in wide x 10 in deep | 0.51 cu yd |
| Large footing example | 24 in wide x 12 in deep | 0.74 cu yd |
Concrete footing material cost per linear foot
Uses $125-$165 per cubic yard as a broad ready-mix material reference before waste, labor, forms, excavation, and fees.
| Footing size | Cubic yards per linear ft | Material per linear ft |
|---|---|---|
| 12 in x 6 in | 0.019 cu yd | $2.31-$3.06 |
| 16 in x 8 in | 0.033 cu yd | $4.12-$5.43 |
| 20 in x 10 in | 0.051 cu yd | $6.43-$8.49 |
| 24 in x 12 in | 0.074 cu yd | $9.26-$12.22 |
Before you calculate
- Measure the formed dimensions, not just the finished visible surface.
- Break complex foundations into separate rectangular sections.
- Use thickness in inches and keep waste visible for excavation and form variation.
Common mistakes
- Missing thickened edges, grade beams, steps, or separate footing runs.
- Using plan dimensions without checking actual forms.
- Treating a material calculator as structural design.
Formula
cubic yards = (length * width * (thickness / 12) / 27) * (1 + wastePercent / 100)
Assumptions
- Width is entered as the calculator width field in feet.
- Thickness is entered in inches.
- This is a quantity estimate, not a structural design.
Concrete footing calculation example
Project: Strip footing for a 30 x 40 ft house foundation, 16 inches wide x 8 inches deep, with 10% waste.
Perimeter = (30 + 40) x 2 = 140 linear feet.
cubic yards = (140 x 1.33 x 0.67) / 27 x 1.10 = about 5.07 cubic yards
- Cubic yards before waste: about 4.61 cu yd
- With 10% waste: about 5.07 cu yd
- Ready-mix planning quantity: about 5.25 cu yd if rounded to the nearest quarter yard
- Material reference: about $634-$837 at $125-$165 per cu yd
- 80 lb bag equivalent: about 229 bags using 0.60 cu ft per bag
How to use this footing concrete calculator
- Length: enter the total linear feet of one footing run. For a full foundation perimeter, calculate each wall or run separately.
- Width: enter footing width in feet. For example, 16 inches is 1.33 ft.
- Thickness: enter footing depth in inches. This is the vertical concrete depth used for volume.
- Waste: use a planning buffer such as 10% when forms, excavation variation, or ordering variance may affect the pour.
- Add results from multiple runs, pads, corners, or stepped sections to get the total order quantity.
Before you buy materials
- Confirm dimensions, reinforcement, and inspection requirements before ordering concrete.
- Use the estimate as a quantity planning number for supplier conversations.
FAQ
What is the example concrete footing cubic-yard result?
Use length, width, thickness or depth, and waste, then calculate the planning result. In the default example, the result is 3.26 cubic yards.
How deep should a concrete footing be?
Footing depth depends on local frost depth, soil, load, and building requirements. As a planning reference, warm-climate footings can be much shallower than cold-climate footings, where frost depth may be several feet. Verify the required depth with local code, permit drawings, or a qualified professional before pouring.
How wide should a concrete footing be?
A common planning rule is that a footing is often wider than the wall it supports. For example, a quantity estimate might use a 16 inch wide footing under an 8 inch block wall. Final width depends on load, soil bearing, wall type, and local requirements.
How much concrete do I need for a house foundation footing?
For a simple example, a 30 x 40 ft foundation perimeter is 140 linear feet. At 16 inches wide and 8 inches deep, it needs about 4.61 cubic yards before waste, or about 5.07 cubic yards with 10% waste.
What PSI concrete should I use for footings?
Concrete strength should follow the project plans and local requirements. Broad residential planning references often discuss mixes around 3,000-4,000 PSI, but this calculator does not choose a structural mix design.
How do I calculate concrete for a footing?
Use cubic yards = length x width x depth in feet / 27, then add waste if needed. Example: 40 ft x 1.33 ft x 0.67 ft / 27 x 1.10 = about 1.45 cubic yards.
Should I calculate each footing section separately?
Yes. Calculate each straight run, corner pad, stepped section, or thickened area separately when dimensions change, then add the cubic yards together for the total order.
What is the example concrete footing result?
Using the default inputs, the example result is about 3.26 cubic yards. The calculation uses slab length, width, thickness, and waste. Use a dedicated footing cost calculator when you need a dollar estimate.
Related calculators
This calculator is for planning estimates only. Verify final quantities with product labels, project conditions, and a qualified professional when accuracy matters.