Concrete Cubic Yard Calculator

Calculate exact concrete volume, bag counts, weight, and cost. Download a full PDF estimate or share your calculation.

Imperial
Metric
Total length
Total width
4" standard
Across
Height
* Short arm length is measured from the outside of the long arm.
Pours
Default 10%
USD
Live 3D Preview

How to Use

  • Select your project shape from the dropdown.
  • Enter your dimensions. The 3D shape and results update live as you type.
  • Toggle between Imperial and Metric units as needed.
  • Adjust waste percentage and cost per cubic yard for accurate estimates.
  • Click "Share" to copy a link with your exact calculation, or download a PDF report.

Formula Used

Volume = Length ร— Width ร— Thickness

1 Cubic Yard = 27 Cubic Feet = 46,656 Cubic Inches.
Standard concrete weight: 133 lbs per cubic foot (2,400 kg per cubic meter).

Frequently Asked Questions

How do I calculate the amount of concrete needed?
Multiply length ร— width ร— thickness to get volume, then convert to cubic yards.

How many bags of concrete equal one cubic yard?
Approximately 90 bags of 40lb, 72 bags of 50lb, 60 bags of 60lb, or 45 bags of 80lb.

What's the minimum thickness for a concrete slab?
4 inches is standard for patios and sidewalks. Driveways should be 5-6 inches.

Pro Tips

  • Waste Factor: Always add 5-10% for spillage, over-excavation, and uneven subgrades.
  • Magic Number 81: For a 4" thick slab, 81 sq ft equals 1 cubic yard (27 cu ft รท 0.33 ft).
  • Ordering Ready-Mix: Most companies require a minimum order (often 1-2 cu yds) and charge short-load fees for smaller amounts.