Concrete Footing Calculator – Simple, Accurate, and Builder-Friendly
Use this free concrete footing calculator to estimate concrete for strip (continuous), pad (isolated), and pier (cylindrical) footings. Enter a few dimensions, select your unit system, add an optional waste allowance, and instantly see total concrete volume, bag counts, and an optional cost estimate. You can add multiple sections and get one clean total for the job.
How the Calculator Works
- Strip/Pad (rectangular):
V = L × W × T - Pier (cylindrical):
V = π × (D/2)² × H - Waste allowance:
Vfinal = V × (1 + waste%) - Bags:
bags = Vfinal ÷ bag_yield(you choose bag size) - Cost (optional):
cost = Vfinal × price_per_m³(or per yd³ in imperial)
Practical Tips
- Check local codes: minimum depth, cover, and frost/soil requirements vary by location.
- Waste 5–15%: tight forms and careful mixing can reduce waste; complex digs may need more.
- Ready-mix vs bags: bags become impractical above ~0.3–0.5 m³.
- Rebar & cover: even spacing and adequate cover (e.g., 40–75 mm) improve durability.
Frequently Asked Questions
What’s the difference between strip, pad, and pier footings?
Strip footings run continuously under walls; pad footings sit under point loads like posts; pier footings are cylindrical columns that transfer loads to deeper soil.
How much waste should I allow?
10% is a sensible default. Increase if the excavation is irregular, access is difficult, or you’re hand-mixing.
Can I use this for engineering design?
No—this tool is for estimating materials only. Always consult local codes and a qualified engineer for structural design.
Related Calculators
- Concrete Slab Calculator – slabs, paths, and patios
- Gravel Calculator – sub-base material volumes
- Stone Calculator – decorative/landscape stone estimates
Estimates only. Always verify onsite and follow local building regulations.
Important Estimate Disclaimer
The results provided by this calculator are intended as general estimates only and should not be considered precise engineering measurements. Actual material requirements, costs, and quantities can vary significantly based on site conditions, local building codes, soil type, reinforcement requirements, climate exposure, and the intended use of your project.
These calculators are designed to help you plan and budget your project more effectively, but they do not replace professional advice from a qualified contractor, engineer, or building inspector. Always verify your calculations and assumptions with trained professionals before placing material orders or commencing construction.
For more information on the assumptions, formulas, and data used in these tools, see our Data Sources and Methodology pages.
Material estimates, cost figures, and volume calculations are approximate and may not reflect your actual requirements. Always double-check dimensions and project-specific needs, and consider adding a contingency allowance for waste, over-excavation, and unforeseen conditions.
If you are unsure about any aspect of your project — including structural requirements, reinforcement needs, drainage, or load-bearing capacity — consult with a licensed professional before proceeding.