How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches and price per cubic yard.
- Read the results.
This calculator turns your slab dimensions and material price into the exact numbers you need to order concrete. By converting length, width, and thickness into cubic yards, you instantly see the volume, then multiply by your price per cubic yard for an accurate cost estimate. It also breaks the volume into cubic feet and tells you how many 80‑lb bags are required (each bag = 0.6 ft³). Knowing the bag count helps avoid short‑orders that delay projects, while the cubic‑yard figure matches how suppliers price concrete. Read the results: Cubic Yards – what the truck will deliver, Estimated Cost – your budget line, Bags – how many mix bags to buy, Cubic Feet – handy for smaller jobs. Use the numbers to compare quotes or plan a waste allowance for a smoother build.
Pro tips
- Add 5‑10% extra volume for spillage and uneven sub‑grade.
- Round up the bag count to the next whole bag to ensure you don’t run short.
- Order concrete by the cubic yard; suppliers often have a minimum load.
- Double‑check thickness units – the calculator expects inches, not centimeters.
Real-life examples
- Homeowner pouring a 12‑ft by 10‑ft patio 4‑in thick.
- Contractor estimating concrete for a 30‑ft wide driveway 6‑in thick.
- DIYer buying bags for a 6‑ft by 8‑ft garden bench foundation 3‑in thick.
Case study
Mike needed a 10 × 12 ft slab 4 in thick. The calculator showed 1.11 cubic yards, $1,332 cost, and 206 bags. He ordered exactly that, avoided a $200 over‑order, and finished on schedule.