How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches.
- Read cubic yards, bags, and cubic feet results.
What it does – The calculator turns your slab dimensions (length, width, thickness) into three practical measures: total cubic feet, cubic yards, and the number of 80‑lb bags needed. Knowing cubic yards tells you what the supplier will charge, while bag count helps you plan purchases. The tool uses the standard conversion of 27 ft³ = 1 yd³ and the industry fact that one 80‑lb bag yields about 0.6 ft³. How to read – The cubic‑feet figure is the raw volume, divide by 27 for cubic yards, and divide by 0.6 (round up) for bags. Accurate estimates prevent surprise trips to the hardware store and keep your project on schedule. Whether you’re pouring a driveway, a patio, or a foundation, the calculator gives you a clear purchasing plan in seconds.
Pro tips
- Add about 10% extra to the bag total for waste.
- Always round up to the next whole bag; you can’t buy a fraction.
- Order bags in multiples of 10 when possible for easier delivery.
- Convert thickness from inches to feet before entering to avoid errors.
Real-life examples
- Homeowner pouring a 12‑ft by 20‑ft garage floor.
- Contractor estimating concrete for a 6‑in thick sidewalk.
- DIY enthusiast planning a backyard patio slab.
Case study
Mike needed a 10 × 12 ft patio 4 in thick. Using the calculator he saw the job required 1.23 yd³, about 56 bags. He ordered 60 bags, avoided a second delivery, and finished on budget.