How to use it
- Enter length in feet
- Enter width in feet
- Enter thickness in inches
- Read cubic yards, bags and cubic feet results
What it does – The tool converts the length, width and thickness you enter into three useful figures: cubic yards for concrete delivery, cubic feet for site calculations, and the number of 80‑lb bags required. Why it matters – Accurate cubic‑yard estimates prevent over‑ or under‑ordering, saving money and time. Bag counts let you know exactly how many packages to buy, avoiding last‑minute trips. How to read the results – Cubic yards are shown to two decimal places; bags are always rounded up to the next whole bag; cubic feet is the exact volume. You can also compare different slab sizes side by side by entering new dimensions and noting how the totals change. This makes it easy to decide the most efficient thickness for your project while staying within budget. Use the numbers to request quotes, schedule deliveries, or plan your material budget. The calculator is instant, free and requires no registration.
Pro tips
- Add about 10% extra for waste when calculating bags
- Always round up the bag total to the next whole bag
- Order a little more than calculated to cover settling and spillage
- Convert thickness from inches to feet before entering to avoid errors
Real-life examples
- A homeowner estimating concrete for a new patio slab
- A contractor planning material for a garage floor pour
- A DIY enthusiast sizing a concrete driveway extension
Case study
Sam entered a 12 ft × 10 ft slab at 4 in thickness, got 0.74 cubic yards and 13 bags, ordered 14 bags, and finished without a single run‑out, saving time and extra delivery fees.