Concrete Yard Calc Calculator

Calculate your concrete yardage instantly and free – get cubic yards, bags, and cubic feet for any slab size.

  • 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. Click Calculate to see cubic yards, bags, and cubic feet.

Concrete Yard Calc turns the dimensions of your slab into the exact amount of concrete you need. You type length, width, and thickness, and the tool instantly returns three values: total cubic yards (the standard ordering unit), the number of 80‑lb bags based on the constant 0.6 ft³ per bag, and the raw cubic‑foot volume. Knowing cubic yards helps you compare quotes from suppliers, while the bag count tells you how many packages to order. The cubic‑foot figure is useful for checking calculations or for projects that require precise volume. All results are shown with two decimal places, so you can round up safely. No guesswork, no hidden fees—just a clear, free estimate for your concrete project. You can also compare the yardage to the minimum delivery size of most mixers to avoid extra trips. If you’re working with a contractor, share the cubic‑yard figure to ensure accurate pricing.

Pro tips

  • Add 5‑10% extra volume for waste and spillage.
  • Round up bag count to the next whole bag.
  • Order bags in multiples of 5 to simplify delivery.
  • Double‑check thickness conversion from inches to feet before entering.

Real-life examples

  • Homeowner pouring a 12 ft × 10 ft patio 4 in thick.
  • Contractor estimating concrete for a 30 ft × 20 ft driveway 6 in thick.
  • DIYer planning a 8 ft × 8 ft garden walkway 3 in thick.

Case study

Mike needed a 10 ft × 12 ft patio at 4 in depth. Using the calculator he saw he required 1.23 cubic yards, which translated to 56 bags. He ordered exactly that amount, avoided a costly over‑order, and his project stayed on budget.

Frequently asked questions

How do I convert thickness in inches to feet?
Divide the inches by 12; the calculator does this automatically when you enter the thickness.
Why does the bag count differ from the cubic‑yard total?
Bags are based on 0.6 ft³ per 80‑lb bag, while a cubic yard is 27 ft³, so the conversion yields a different number.
Should I round up the bag number?
Yes, always round up to the next whole bag to ensure you have enough mix.
Can I use the results for ordering ready‑mix concrete?
The cubic‑yard figure is exactly what ready‑mix suppliers quote, so you can give them that number.
What if my slab has a non‑rectangular shape?
Break the area into rectangles, calculate each section separately, then add the results.