Concrete volume calculator
Estimate slab or cylinder volume with unit-aware inputs.
How to use Concrete volume calculator
The Concrete volume calculator estimates cubic meters of concrete for a rectangular slab or a cylinder such as a column or post hole. A slab uses length times width times depth; a cylinder uses pi times the radius squared times height. It shows the net volume and the volume with an extra percentage, 5 percent by default, for spillage and uneven ground.
- Enter the requested values in the settings panel.
- Adjust the basic settings, then open Advanced mode for export and fine-tuning options. Custom settings stay active when the panel is closed.
- Run concrete volume calculator, review the output, then use the available copy or download controls.
What this tool supports
Estimate slab or cylinder volume with unit-aware inputs.
- Shape
- slab · cylinder
- Length / cylinder diameter (m)
- Range: 0.0001 to 1000000000000
- Width (m; slab)
- Range: 0.0001 to 1000000000000
- Depth / cylinder height (m)
- Range: 0.0001 to 1000000000000
- Extra (%)
- Range: 0 to 100
Limits and processing
Local bounded calculations. Numeric inputs must be finite and within the visible ranges. Lists and tables have operation-specific limits. Models, estimates and supplied rates must be checked against your intended use.
Frequently asked questions
How much concrete do I need for a slab?
Choose slab and enter length, width and depth in meters. The default 4 m by 3 m slab at 0.1 m deep needs 1.2 cubic meters net, or 1.26 cubic meters with the 5 percent extra.
How do I calculate concrete for a round column or post hole?
Choose cylinder, enter the diameter in the length field and the height or depth in the depth field. The volume is pi × (diameter ÷ 2)² × height, in cubic meters. The width field is ignored for cylinders.
How much extra concrete should I order?
The calculator adds a percentage you choose from 0 to 100, with 5 percent as the default. The right margin depends on formwork, ground and delivery; confirm it with your supplier and local requirements.
Where is my input processed?
This operation processes its source in your browser. Copy and download are explicit actions; source input is not saved in an account or history.
What are the input limits?
Local bounded calculations. Numeric inputs must be finite and within the visible ranges. Lists and tables have operation-specific limits. Models, estimates and supplied rates must be checked against your intended use.