Example 1 — 5×4 m slab
- 5 × 4 × 0.1 m
- +5% waste
- 0 deductions
2.1 m³
A basic slab case where volume is the starting point for ordering and cost planning.
Concrete volume calculator
Volume from length × width × height × count, minus deductions, plus waste %.
Also useful: mortar requirement, cement in mortar.
Results
Enter data and click Calculate.
How the results are calculated
V = length × width × height × count × (1 + waste/100), then subtract deducted volume. The result is floored at 0.
How to use this calculator
- Enter length, width and height / thickness.
- Set the number of identical elements (default 1).
- Optionally subtract deductions and set waste % and price.
- Calculate — you will see volume, indicative truck loads (~6 m³) and estimated cost.
Usage examples
Example 2 — Strip footing
- 10 × 0.4 × 0.5 m
- +10% waste
- 0 deductions
2.2 m³
With larger pours, even a modest waste allowance can change cost and delivery planning.
Example 3 — Six posts
- 0.3 × 0.3 × 1 m
- × 6
- +5% waste
0.567 m³
Shows why counting identical elements early helps when timing a pour.
Frequently asked questions
How is concrete volume calculated?
Volume = length × width × height × count, minus deductions, then × (1 + waste%). Example: 5×4×0.1 m → 2 m³, +5% waste → 2.1 m³.
What should I enter as deductions?
Volume of embedded elements or openings that displace concrete (e.g. pipes, blockouts), in the same volume unit.
Why multiply by the number of elements?
For repeated identical pours (posts, footings) count multiplies the single-unit volume before waste.
How many truck loads do I need?
Divide the total volume by a standard 6 m³ ready-mix truck load and round up to plan deliveries.
What waste % should I use for a slab?
Typically 5–10% for slabs and footings to cover spillage and formwork tolerance.
How do I switch metric ↔ US units?
Use the units selector in the header. Labels and examples update automatically.
Is it worth adding concrete reserve?
Yes, especially if the substrate is not perfectly even or there is a risk of small execution differences.
What should I calculate after concrete volume?
Most often cost, bag count, or transport/load planning depending on how the work will be carried out.