How to use it
- Enter length in feet
- Enter width in feet
- Enter thickness in inches
- Read cubic yards, bags and cubic feet results
The Work Out How Much Concrete I Need Calculator takes the length, width, and slab thickness you enter and instantly returns three useful figures: total cubic yards, the number of 80‑lb bags, and total cubic feet. Knowing the cubic yards tells you how much material to order from the supplier, while the bag count translates that volume into the most common retail unit. The cubic‑feet result lets you double‑check the math or compare against other project estimates. The tool does all the conversions for you—no need to remember that one yard equals 27 cubic feet or that each 80‑lb bag yields about 0.6 cubic feet. Just plug in your dimensions, read the three results, and you’re ready to place an accurate order without costly over‑ or under‑estimates.
Pro tips
- Add 5‑10% extra volume for waste and spillage
- Round the bag count up to the nearest whole bag
- Order a little more than calculated to avoid shortages
- Double‑check thickness conversion from inches to feet before entering
Real-life examples
- A homeowner pouring a 12‑ft by 16‑ft patio 4 in thick
- A contractor estimating concrete for a 30‑ft driveway 6 in thick
- A DIYer planning an 8‑ft by 8‑ft garden walk 3 in thick
Case study
Mike needed a 10 ft × 10 ft patio 4 in thick. Using the calculator he saw he required 1.24 cubic yards, about 56 bags, and 33.3 cubic feet. He ordered 57 bags, avoided a costly shortfall, and completed the patio on schedule.