Calculate concrete, rebar, and formwork needed for strip, pad, or raft foundations.
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How to Use This Calculator
<h4>How to Use</h4><ol><li>Select the foundation type (strip, pad, or raft).</li><li>Enter the dimensions – length, width, and depth.</li><li>Adjust waste percentage as needed.</li><li>Review concrete volume, rebar, and formwork estimates.</li></ol><h4>Tips</h4><ul><li>Strip foundations are typically 450–600 mm (18–24 in) wide and 225+ mm (9+ in) deep.</li><li>Raft foundations spread the load over the entire building footprint.</li><li>Always consult a structural engineer for load-bearing calculations.</li></ul>
Common Questions
What type of foundation do I need?
Strip foundations suit most houses on stable soil. Pad foundations are for point loads like columns. Raft foundations are used on weaker soils to spread the load.
How deep should a foundation be?
In the UK, minimum depth is typically 1 m below ground. In the US, footings should extend below the frost line, which varies by region.
What concrete mix should I use?
For foundations, use a minimum C25/30 (GEN 3) mix. For aggressive soil conditions, sulfate-resistant cement may be required.