Concrete Footing Calculator
Concrete volume for strip or column footings.
Enter your values
Enter the footing length in ft.
Enter the footing width in ft.
Enter the footing depth in ft.
Enter the waste allowance in %.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Concrete needed
- 2.44 cu yd
- Volume (no waste)
- 2.22 cu yd
- Cubic feet
- 60 cu ft
- 80 lb bags equivalent
- 110
Quick answer
Footing volume is length times width times depth, converted to cubic yards with a waste allowance.
yd3 = (L x W x D) / 27 x (1 + waste%)
At a glance
| What it does | Concrete volume for strip or column footings. |
|---|---|
| Category | Home & DIY |
| Inputs needed | Footing length, Footing width, Footing depth, Waste allowance |
| Main output | Concrete needed |
| Formula | yd3 = (L x W x D) / 27 x (1 + waste%) |
| Cost | Free — no sign-up, no download |
How to use the Concrete Footing Calculator
- 1Measure the footing length, width and depth in feet.
- 2Convert cubic feet to cubic yards, the unit ready-mix is sold in.
- 3Add 10% waste for uneven trench sides and spillage.
Inputs explained
- Footing length(ft)
- Enter the footing length in ft.
- Footing width(ft)
- Enter the footing width in ft.
- Footing depth(ft)
- Enter the footing depth in ft.
- Waste allowance(%)
- Enter the waste allowance in %.
Worked example
Using the values the calculator loads with:
Inputs
- Footing length40 ft
- Footing width1.5 ft
- Footing depth1 ft
- Waste allowance10 %
Results
- Concrete needed2.44 cu yd
- Volume (no waste)2.22 cu yd
- Cubic feet60 cu ft
- 80 lb bags equivalent110
Frequently asked questions
How deep should footings be?
Deep enough to reach below the local frost line — check your building department.
Can I use bagged concrete for footings?
Yes for small footings, but ready-mix is far more economical above about 1-2 cubic yards.
What do I need to enter into the Concrete Footing Calculator?
Just 4 values: footing length, footing width, footing depth, waste allowance. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Concrete Footing Calculator work out the answer?
Footing volume is length times width times depth, converted to cubic yards with a waste allowance. It applies the formula yd3 = (L x W x D) / 27 x (1 + waste%) and shows the working so you can check each step by hand.
Is the Concrete Footing Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.