Concrete Yardage Calculator
Calculate concrete yardage for slabs, footings, columns and any shape. Get cubic yards instantly from feet or meters. Free concrete yardage estimator.
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How to Calculate Cubic Yards of Concrete
Figuring out the exact yardage for your concrete project doesn't have to be complicated. The basic math requires you to multiply the length, width, and depth of your pour area. However, the most critical step is ensuring all of your measurements are in feet before you multiply them together. If your slab is 4 inches thick, you must first divide 4 by 12 to convert it to feet (0.33 feet).
Once you multiply the length, width, and depth in feet, you will have your total volume in cubic feet. Because ready-mix concrete is always sold and delivered by the cubic yard, you must then divide your total cubic feet by 27 (since there are 27 cubic feet in one cubic yard). Finally, it is standard contractor practice to add a 10% waste margin to your final yardage to account for an uneven sub-base or minor spillage.
The Concrete Yardage Formula
Rectangular: yd³ = (L × W × D) ÷ 27
Circular: yd³ = (π × r² × D) ÷ 27
Add waste: Final yd³ = Result × 1.10
Yardage Reference Chart
| Project | Size | Thickness | Cubic Yards |
|---|---|---|---|
| Small patio | 10×10 ft | 4" | 1.23 yd³ |
| Standard driveway | 20×20 ft | 4" | 4.94 yd³ |
| Garage floor | 20×24 ft | 4" | 5.93 yd³ |
| Sidewalk | 50×4 ft | 4" | 2.47 yd³ |
Frequently Asked Questions
How do I figure out cubic yards of concrete?
Multiply length × width × depth (all in feet), then divide by 27. For a 10×10 ft slab at 4 inches (0.333 ft): 10 × 10 × 0.333 = 33.3 ft³ ÷ 27 = 1.23 cubic yards. Add 10% waste = 1.36 yd³.
How many cubic yards in a bag of concrete?
One 80lb bag yields 0.022 cubic yards. You need 45 bags per cubic yard.
How much does a cubic yard of concrete cost?
Ready-mix concrete typically costs $120–$200 per cubic yard depending on location and mix strength.
How to calculate yardage for a round concrete pour?
Use the formula: π × radius² × depth ÷ 27. For a 12-inch diameter, 3 ft deep sonotube: π × 0.5² × 3 ÷ 27 = 0.087 yd³ per tube.