Concrete Footing Calculator
Estimate concrete volume, cubic yards or metres, bag quantity, excavation footprint and ready-mix cost for continuous or isolated footings.
Default project preview
2.44 yd³
Concrete bags
110
Base volume
2.22 yd³
Excavation footprint
60 ft²
Total footing length
30 ft
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Footing length
Enter this project assumption in ft. The current imperial default is 30 ft.
Footing width
Enter this project assumption in ft. The current imperial default is 2 ft.
Footing thickness
Enter this project assumption in ft. The current imperial default is 1 ft.
Number of footings
Enter this project assumption in a unitless value. The current imperial default is 1. Minimum: 1.
Extra allowance
Enter this project assumption in %. The current imperial default is 10 %. Minimum: 0. Maximum: 50.
Concrete yield per bag
Enter this project assumption in ft³. The current imperial default is 0.6 ft³.
Ready-mix price
Enter this project assumption in per yd³. The current imperial default is 165 per yd³. Minimum: 0.
Price per bag
Enter this project assumption in a unitless value. The current imperial default is 7. Minimum: 0.
How to read the outputs
Concrete bags
0.6 ft³ yield each. Default preview: 110.
Base volume
before allowance. Default preview: 2.22 yd³.
Excavation footprint
plan area. Default preview: 60 ft².
Total footing length
all footings. Default preview: 30 ft.
Ready-mix cost
entered volume rate. Default preview: $403.33.
Bagged cost
rounded full bags. Default preview: $770.00.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Base volume = length × width × thickness × quantity. Order volume = base volume × allowance. Bags = round up (order volume ÷ bag yield).
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 29, 2026
Use this calculator to estimate concrete volume for continuous strip footings from total length, width and depth. It supports material ordering only; footing dimensions, reinforcement, bearing and frost protection must come from the project design and site conditions.
Calculation steps
- 1Convert width and depth to the same length unit.
- 2Multiply total footing length × width × depth.
- 3Convert cubic feet to cubic yards or cubic metres as needed.
- 4Add the entered placement allowance and follow the supplier rounding rule.
Worked numerical example
A 60 ft footing that is 20 in wide and 10 in deep contains about 8.23 yd³ before allowance. Adding 10% produces 9.05 yd³, so a ready-mix order would normally be rounded to the supplier increment above that quantity.
Purchasing and rounding
Ready-mix suppliers may sell in quarter-yard or other increments and may charge short-load fees. Bagged concrete must be rounded to full bags using the exact published yield.
Interpret the result
The result represents geometric concrete volume. Excavation irregularity, overdig, keyways and concrete left in the pump or chute can increase actual use.
Page-specific assumptions
- Uniform rectangular footing section.
- Entered dimensions are concrete dimensions, not excavation dimensions.
- No separate piers or thickened pads are hidden in the length.
- Allowance reflects field placement conditions.
Common mistakes
- Using trench width instead of designed footing width.
- Mixing inches and feet.
- Forgetting intersecting footing runs.
- Rounding the order downward.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Concrete Footing Calculator questions
Should footing concrete include extra material?+
An allowance helps cover uneven excavation, spillage and measurement differences. Large pours should be confirmed with the supplier.
Can this determine footing dimensions?+
No. Footing size depends on loads, soil bearing, frost depth and code requirements.
When is ready-mix more practical than bags?+
Ready-mix is usually more practical as volume and placement speed increase, but minimum-load and delivery charges matter.