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.