Concrete Calculator for Slabs and Pads
Calculate concrete volume, order quantity and dry-mix bags from slab dimensions.
Formula
Planning estimate. Check product specifications and local requirements before purchasing.
Worked example: Concrete Calculator
Measurements in this example
| Length | 6 m |
|---|---|
| Width | 4 m |
| Thickness | 10 cm |
| Waste allowance | 5 % |
| Yield per bag | 12 l |
| Bag weight | 25 kg |
Calculated quantities
| Volume | 2.52 m³ |
|---|---|
| Bags | 210 × 25 kg |
| Area | 24 m² |
What to check
This calculation uses: Length, Width, Thickness, Waste allowance, Yield per bag, Bag weight. It returns: Volume, Bags, Area.
Use dimensions from the structural drawings and check excavation against them before concrete or steel is ordered.
The ordering figure excludes pump priming, severe overbreak and unrecorded level changes unless they are included in the inputs.
Use the units beside each field. The values in the worked example are starting inputs; replace them with your measurements and the specifications of your material.
Compare alternatives
Open a tool, enter your measured dimensions, then save an estimate. Keep another version if you want to compare products or allowances.