How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches.
- Click Calculate to see cubic yards, bags, and cubic feet.
What it does – The Quikrete Slab Calculator takes the length, width, and thickness you input and instantly returns three useful measures: total cubic feet of concrete, the equivalent in cubic yards, and how many 80‑lb bags you’ll need (each bag yields about 0.6 ft³). Knowing the exact volume prevents ordering too little, which can delay a project, or too much, which wastes money. The results are shown side‑by‑side so you can compare the larger yardage to the more precise bag count. For example, a 12 ft × 12 ft slab that is 4 in thick works out to roughly 48 ft³, about 1.8 yd³, and 80 bags. Use the numbers to place an accurate order and keep your budget on track. You can also adjust the dimensions to see how a deeper or larger slab changes the material requirements, helping you plan for future expansions or design changes.
Pro tips
- Add 5‑10% extra for spillage and uneven subgrade.
- Round bag count up to the nearest whole bag; you can’t buy a fraction.
- Order bags in multiples of 10 to reduce shipping fees.
- Double‑check thickness conversion (inches to feet) before calculating.
Real-life examples
- Homeowner building a 10 ft × 20 ft patio.
- Contractor estimating concrete for a garage floor.
- DIY enthusiast planning a garden walkway slab.
Case study
Mike needed a 12 ft × 12 ft garage floor 4 in thick. Using the calculator he saw he required 48 ft³, 1.8 yd³, and 80 bags. He ordered exactly that amount, avoided a costly over‑order, and finished the project on schedule.