Concrete Calculator
Planning a patio, driveway, or post hole? Use our engineering-grade calculator to determine exactly how many cubic yards to order or how many bags to buy from the hardware store.
Project Dimensions
How to Calculate Concrete
Concrete is sold by volume (Cubic Yards) or by weight (Bags). The golden rule of concrete is: Always round up. Running out of concrete in the middle of a pour creates a "cold joint" that weakens the structure.
Step 1: Calculate Volume in Feet
Multiply Length × Width × Thickness.
Note: If thickness is in inches, divide by 12 first. Example: 4 inches = 0.33 feet.
Step 2: Convert to Yards
Divide cubic feet by 27.
Volume (yds) = Cu. Ft / 27
Quick Bag Reference Chart
Approximate yield for Quikrete or Sakrete mixes:
| Bag Size | Yield (Cu. Ft) | Bags per Yard |
|---|---|---|
| 80 lb | 0.60 | 45 |
| 60 lb | 0.45 | 60 |
| 50 lb | 0.37 | 72 |
| 40 lb | 0.30 | 90 |
Frequently Asked Questions
Frequently Asked Questions
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