How to use it
- Enter length in feet, width in feet, and thickness in inches.
- Click Calculate to see cubic feet, cubic yards, and bag count.
- Review the numbers and adjust for waste as needed.
The Quikrete Bag Calculator turns your slab dimensions into three concrete metrics you need before you order: cubic feet, cubic yards and the number of 80‑lb bags. Knowing the exact volume prevents over‑ordering, saves money, and keeps your project on schedule. The tool first converts thickness from inches to feet, multiplies length, width and thickness to get cubic feet, then divides by 27 for cubic yards. Finally it divides cubic feet by 0.6 cf per bag to show how many bags are required. Read the results: cubic feet tells you the raw volume, cubic yards is the industry‑standard shipping unit, and bags is what you’ll actually purchase. Use the numbers to plan waste allowance and delivery. You can also compare different slab thicknesses instantly to see how material needs change.
Pro tips
- Add 5‑10% extra for spillage and breakage.
- Round up bag count to the next whole bag; you can’t buy a fraction.
- Order bags in multiples of 5 to qualify for bulk discounts.
- Double‑check thickness conversion; a common mistake is using inches as feet.
Real-life examples
- Planning a 6‑ft deep concrete driveway slab.
- Estimating material for a backyard patio with a 4‑inch thick slab.
- Calculating concrete for a garage floor renovation.
Case study
Mike needed a 12x10 ft patio 4 in thick. Using the calculator he saw he needed 56 bags instead of guessing 70, saving $200.