Concrete volumes
Pad foundation volume
- where
- total concrete volume (m³)
- number of pads
- pad length (m)
- pad width (m)
- pad depth (mm)
Explain this equation
Works out concrete for one or more pad foundations under posts or columns.
Each pad is a rectangular block: length times width times depth, with the depth converted from mm. Multiplying by the number of pads gives the total.
Volume of a block, times the number of blocks.
Sense check: four 1 × 1 m pads 600 mm deep is 2.4 m³.
Watch out: pad sizes depend on loads and ground conditions; take them from the engineer's design.
Works out the concrete in a set of identical rectangular pad foundations, such as those under columns, posts or a timber frame.
Enter your values to see the result.
Good to know
Enter the pad as dug, not just the design size, if the excavation is larger. Group pads of different sizes and run the calculator once for each group.
Common mistake
Counting the pads on one elevation and forgetting the internal or corner pads shown only on the plan.
Limits
Rectangular pads of uniform depth. Stepped or tapered pads should be split into simple blocks. Pad sizes come from the structural design.
Sources
- Geometry: prism volume = plan area × depth; cylinder volume = π d²/4 × h
Results are calculations from the published methods and figures shown, and depend on the data you enter. Follow BS 8500, BS EN 206, BS EN 752, Building Regulations Part H, manufacturers’ data and your engineer’s design. Structural concrete and foundations need a competent designer.