Concrete Calculator – Slabs, Footings, Columns, Beams And Stairs
This all-in-one Concrete Calculator helps you estimate how much concrete you need for common structural elements. You can switch between metric and imperial units, add a waste percentage, and see approximate bag counts for ready-mix concrete.
1. Concrete Slab Volume
For slabs like driveways, floors, or patios, volume is based on length × width × thickness. In metric:
In imperial, the calculator converts feet and inches into cubic feet and then cubic yards. A waste allowance helps cover spill, uneven ground, and over-excavation.
2. Footing And Foundation Concrete
Strip footings and trench foundations are generally long rectangular sections. The calculator multiplies total length, width, and depth to estimate volume, then adds your chosen waste percentage.
3. Columns And Beams
For columns, the volume for one column is width × depth × height, multiplied by the number of columns. For beams, it is width × depth × length times the number of beams. The calculator adds both parts to show total column and beam concrete together.
4. Stair Concrete (Approximate Triangular Volume)
Straight stairs can be approximated by a triangular prism. The volume is based on stair width, total horizontal run, and total vertical rise:
This gives a quick estimate for the concrete in a solid stair flight.
Units, Bags And Waste
The calculator supports both metric (m, cm, m³) and imperial (ft, in, yd³) systems. It also shows approximate numbers of standard pre-mix concrete bags based on typical yields. These values are for estimation only and can vary by product and mix.
Important Disclaimer
All results are approximate and for planning or educational purposes only. Always check local building codes and consult a qualified engineer, architect, or contractor before ordering materials or starting construction.
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