How it works
Calculate your material requirement
Calculate concrete cubic yards, cubic meters, and ready-mix bag quantities for slabs, footings, and pads.
The formula
Cubic yards = length × width × (thickness ÷ 12) × quantity ÷ 27, increased by the selected waste percentage.
Worked example
A 12 ft × 10 ft slab that is 4 in thick contains 40 ft³, or 1.48 yd³. With 10% extra, plan for approximately 1.63 yd³.
Before you order
- Measure finished dimensions, not excavation dimensions alone.
- Ready-mix suppliers may have minimum order quantities.
- Bag yields vary by manufacturer; verify the yield printed on the bag.