Sq Ft To Cubic Yards Concrete Calculator

Instantly calculate how many cubic yards of concrete you need, plus bags and cubic feet, for free.

  • Free
  • No sign-up
  • Instant results

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How to use it

  1. Enter length in feet.
  2. Enter width in feet.
  3. Enter thickness in inches.
  4. Read cubic yards, bags, and cubic feet results.

What it does – The calculator turns the length and width of your pour (in feet) and the thickness (in inches) into three useful numbers: cubic yards of concrete, the equivalent number of 80‑lb bags, and total cubic feet. Why it matters – Knowing cubic yards lets you order the right amount from the supplier; bag count helps you budget, and cubic feet is handy for comparing different mixes. How to read the results – The cubic‑yard figure is the volume you’ll tell the truck driver. Divide the cubic‑foot result by 0.6 to see how many 80‑lb bags you’ll need, then round up. No guesswork, just clear numbers you can act on. You can also compare multiple projects side‑by‑side by copying the results into a spreadsheet. The tool works instantly in any browser, so you can adjust dimensions on the fly and see how the bag count changes.

Pro tips

  • Add 5‑10% waste to the total volume.
  • Round up bag count to the next whole bag.
  • Order a little extra to avoid shortfalls.
  • Double‑check thickness conversion from inches to feet.

Real-life examples

  • A homeowner pouring a 4‑in driveway slab.
  • A contractor estimating concrete for a patio foundation.
  • A DIY enthusiast planning a small shed floor.

Case study

John needed a 10 × 12 ft slab 4 in thick. Using the calculator he saw he required 1.5 yd³ of concrete, about 67 bags. He ordered 70 bags, avoided a costly delay, and finished on schedule.

Frequently asked questions

How do I convert thickness in inches to feet?
Divide the inch value by 12; 4 in becomes 0.33 ft.
Why does the calculator show bags in addition to cubic yards?
Bags help you budget because concrete is sold by the 80‑lb bag, each yielding about 0.6 ft³.
Should I add extra concrete for waste?
Yes, add 5‑10% to the total volume to cover spillage and uneven subgrade.
What if my slab isn’t a perfect rectangle?
Break the area into rectangles, calculate each, then sum the results.
Is the bag count rounded up automatically?
The tool shows the exact decimal; round up to the next whole bag for ordering.