Concrete Quantity Calculator
Estimate concrete quantities for defined structural elements.
Project & Input Data
An editable user-defined allowance — not a universal engineering requirement.
Engineering Assumptions
- In dimensions mode the element is a regular rectangular prism (slab or footing).
- In direct-volume mode the entered volume is the user's own take-off; only the waste allowance is applied.
- Reinforcement displacement and openings are not deducted.
- All percentages and inputs are user-defined; the calculation is purely arithmetic and assumes no particular code or specification.
Formula Summary
- Dimensions mode: base volume = L × W × D × count
- Direct mode: base volume = entered volume
- Waste volume = base volume × waste%
- Total concrete = base volume + waste volume
Results
Enter your data and press Calculate to see the results.
Engineering Insight
The base volume is the theoretical quantity from the drawings; the waste allowance covers spillage, losses and irregular substrate. Always compare the ordered quantity with available batch and pour sizes.
Recommended Action
Compare the total volume with available truck/mixer sizes, plan the pour sequence before ordering, and confirm quantities against the construction drawings.
Next step
This calculator is fully usable as it is. Professional adds saved projects, calculation history and PDF/Excel reports; Premium adds the integrated workflows and the BOQ generator.
Use this calculator when you need the concrete volume for a footing, slab, column or beam and want a waste allowance applied consistently. You can either enter length × width × thickness × element count, or start from a volume already measured in your take-off.
Method and assumptions
- Dimensions mode: base volume = L × W × D × count
- Direct mode: base volume = entered volume
- Waste volume = base volume × waste%
- Total concrete = base volume + waste volume
- In dimensions mode the element is a regular rectangular prism (slab or footing).
- In direct-volume mode the entered volume is the user's own take-off; only the waste allowance is applied.
- Reinforcement displacement and openings are not deducted.
- All percentages and inputs are user-defined; the calculation is purely arithmetic and assumes no particular code or specification.
Worked example
Two 6.00 m × 4.00 m raft panels, 250 mm thick, with a 5% waste allowance.
| Result | Value |
|---|---|
| Base concrete volume | 12 m³ |
| Waste allowance | 0.6 m³ |
| Total concrete volume | 12.6 m³ |
These figures are produced by the same calculator engine used on this page.
Frequently asked questions
- Does the calculator include reinforcement steel?
- No. It returns concrete volume only. For steel mass and bar counts use the Reinforcement Estimator, which takes your own steel ratio in kg per m³.
- What waste percentage should I use?
- The waste percentage is a project assumption you enter. ALASOS does not assume a figure; use the allowance agreed for your works, method of placing and site conditions.
- Is the result a code check?
- No. It is deterministic quantity arithmetic (volume × count, plus waste). It performs no structural design check against any standard.
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- Reinforcement EstimatorConstruction Calculators
- Formwork CalculatorConstruction Calculators
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Next step
- All Construction Calculators
- Construction Estimation Suite
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