Calculate Concrete for Slabs, Footings, and Columns
Whether you are pouring a driveway, a patio, or a house foundation, knowing the exact volume of concrete is critical. Ordering too little concrete can result in "cold joints" which weaken the structure, while ordering too much wastes budget.
How to Use This Calculator
Our tool works for any rectangular prism shape (slabs, square footings, beams).
- Length & Width: Measure the formwork area.
- Thickness/Depth: This is crucial. Ensure you enter the depth correctly (e.g., for a 6-inch slab, enter 0.5 feet if using Imperial).
- Cement Bags: The calculator assumes a standard structural mix ratio of 1:2:4 (1 part Cement, 2 parts Sand, 4 parts Aggregate). This is the most common ratio for reinforced concrete slabs.
Pro Tips for Builders
Always add a 5-10% safety margin to your order to account for uneven sub-grades, spillage, and formwork deflection. The "Bags" calculation is based on standard 50kg cement bags.