How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches.
- Read cubic yards, bag count, and cubic feet results.
Figure Concrete Slab Calculator lets you input the length, width, and thickness of any slab and instantly see three key numbers: total cubic feet, cubic yards, and the number of 80‑lb bags required. Knowing cubic feet helps you verify the physical size of the pour, while cubic yards is the unit most suppliers use for pricing and delivery. The bag count translates that volume into the exact amount of mix you’ll need, based on the standard 0.6 ft³ per bag. Use the results to order the right quantity, avoid costly over‑orders, and keep your project on schedule. The tool does all the math for you, so you can focus on site prep and finishing. You can also compare multiple slab sizes side by side to choose the most efficient design.
Pro tips
- Add 5‑10% waste allowance to the cubic yards before ordering.
- Always round up the bag count; you can’t buy a fraction of a bag.
- Order a little extra to cover future repairs or slight mis‑measurements.
- Double‑check thickness conversion from inches to feet to avoid under‑estimation.
Real-life examples
- Homeowner planning a backyard patio wants exact material needs.
- Contractor estimating a driveway pour to give an accurate quote.
- DIY enthusiast preparing a garage floor and needs to know how many bags to buy.
Case study
Mike needed a 12 ft × 8 ft patio 4 in thick. The calculator showed 2.4 cubic yards, which meant 4 bags of mix (0.6 ft³ each). He ordered exactly that, saved $150 on excess material, and completed the pour on schedule.