How to use it
- Enter length in feet
- Enter width in feet
- Enter thickness in inches
- Read cubic yards, cubic feet and bag count
Enter the length, width and thickness of the slab you plan to pour and the calculator instantly converts those dimensions to cubic yards, cubic feet, and the number of 80‑lb bags you’ll need. Knowing the exact volume helps you order the right amount of mix, avoid costly over‑orders, and keep your budget on track. The result shows cubic yards for ordering bulk deliveries, cubic feet for comparing to material specs, and bags for retail purchases. Because each 80‑lb bag yields about 0.6 cubic feet, the tool divides the total cubic feet by that constant and rounds up to the nearest whole bag. Use the numbers to confirm quotes from suppliers and to plan waste allowances. You can also adjust the thickness in inches to match foundations, patios, or driveways, and the calculator will recalculate instantly.
Pro tips
- Add 5‑10% waste to the bag count
- Round up the bag total to the next whole bag
- Order extra bags for unexpected depth changes
- Double‑check measurements before submitting
Real-life examples
- A homeowner estimating concrete for a new 12‑ft patio.
- A contractor pricing a 24‑ft driveway slab.
- A landscaper planning a raised garden bed foundation.
Case study
Mike needed 2‑yard concrete for a backyard patio. He entered 12 ft × 12 ft × 4 in, got 0.89 cubic yards, which rounded to 2 cubic yards and 2 bags. He ordered exactly that amount, avoided a $30 over‑order, and finished on schedule.