Slab Price Calculator

Instantly calculate concrete slab volume, bags, and cost – free and instant.

  • Free
  • No sign-up
  • Instant results

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How to use it

  1. Enter length, width, and thickness values.
  2. Input the price per cubic yard.
  3. Click the Calculate button.
  4. Read the cubic yards, bags, and total cost.

What it does – The Slab Price Calculator turns the dimensions of your concrete slab (length, width, thickness) into the exact volume in cubic yards, then multiplies by your price per yard to give an estimated cost. It also tells you how many 80‑lb bags you’ll need, using the standard 0.6 ft³ per bag, and shows the total cubic feet for reference. Why it matters – Knowing volume and bag count before you order prevents over‑buying or shortfalls, saving money and time. How to read the results – Cubic yards is the amount you’ll be billed for, Estimated cost is price × cubic yards, Bags is cubic feet ÷ 0.6 (rounded up), and Cubic feet lets you double‑check the conversion. Add a 5‑10% waste allowance to the bag total to ensure you have enough material for cuts and spillage.

Pro tips

  • Add 5‑10% extra bags for waste and spillage.
  • Always round up the bag count to the next whole bag.
  • Compare supplier prices per cubic yard before ordering.
  • Double‑check thickness conversion from inches to feet.

Real-life examples

  • Homeowner planning a 12 ft × 8 ft patio 4‑in thick.
  • Contractor estimating concrete for a garage floor slab.
  • Landscape designer budgeting for a raised garden bed.

Case study

Mike needed a 10 ft × 6 ft slab 4 in thick for his workshop. Using the calculator, he saw the job required 1.5 cubic yards, 67 bags, and $210 total. He ordered 70 bags, avoided a costly shortfall, and completed the slab on schedule.

Frequently asked questions

How do I convert thickness in inches to feet?
Divide the inches by 12; the calculator does it automatically.
Why does the bag count use 0.6 cubic feet?
An 80‑lb bag of ready‑mix concrete consistently yields about 0.6 ft³, per industry standard.
Should I add waste to the bag total?
Yes, add 5‑10% extra bags to cover cuts, spillage, and uneven subgrade.
What if my supplier quotes price per cubic meter?
Convert the price to per cubic yard (1 yd³ = 27 ft³) or use the calculator with a yard price.
Can I trust the estimated cost?
It’s based on the volume you entered and the price per cubic yard you provided; actual cost may vary with delivery fees or mix variations.