Concrete Volume Estimator
Estimate concrete volume for slabs, footings or round columns in m³, yd³ and ft³, plus premix bags, with waste.
Your inputs
Results
Concrete needed
1.32 m³
- In cubic yards
- 1.726 yd³
- In cubic feet
- 46.62 ft³
- Premix bags
- 78
≈Estimate based on the stated model and assumptions
Notes for this result
- For structural work, follow the engineer’s specification for mix, reinforcement and thickness.
What this calculator does
Order or buy concrete by volume. Bags of premix list their yield; ready-mix is ordered in cubic metres or yards.
Formula and method
Slab = length × width × thickness; Column = π × (diameter ÷ 2)² × depth; Total = volume × count × (1 + waste %); Bags = ceiling(total ÷ bag yield)
Worked example
Calculated by this tool with its default inputs:
Inputs
- Shape: Slab or footing (rectangular)
- Length: 4 m
- Width: 3 m
- Thickness: 10 cm
- Number of identical pours: 1
- Waste / over-order: 10 %
- Yield per bag of premix: 0.017 m³
Results
- Concrete needed: 1.32 m³
- In cubic yards: 1.726 yd³
- In cubic feet: 46.62 ft³
- Premix bags: 78
How to read the results
Ready-mix suppliers often have minimum orders; small jobs may suit bags.
Assumptions and limitations
- Structural work must follow an engineer’s specification.
Questions
How much does an 80 lb bag make?
Typically about 0.6 ft³ (0.017 m³), but check the bag.
Methodology and verification
- Result type
- Estimate based on the stated model and assumptions
- Formula version
- 1.0
- Automated verification
- 3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
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