Concrete Calculator US
Estimate the exact volume in cubic yards, plus the number of Quikrete or Sakrete bags needed for your slab or sonotubes.
Calculate Concrete Yardage for Slabs and Sonotubes
Welcome to ConcreteCalculator.website. If you are building a new driveway pad in Texas or pouring sonotubes for a deck in Ohio, getting your yardage calculation right is incredibly important. In the US, ordering too much ready mix wastes your hard earned money, while running short during a pour results in expensive short load fees from suppliers.
I designed this US concrete calculator to be as simple and accurate as possible:
- Select your preferred measurement system. Most US projects rely entirely on Imperial measurements using feet and inches.
- Select what you are building: a concrete slab, deep sonotubes or fence posts, or standard stairs.
- Enter your exact dimensions. Ensure you measure the exact depth of your forms or excavation.
- Hit calculate to get your volume in cubic yards and instantly see how many standard bags of Quikrete or Sakrete you need to pick up from The Home Depot or Lowe's.
How Do You Calculate Cubic Yards of Concrete?
If you prefer to crunch the numbers manually, the formula is quite straightforward. You just need to ensure all your measurements are converted to feet before multiplying.
Cubic Yards Formula: Length in feet multiplied by Width in feet multiplied by Depth in feet. Take that total number and divide by 27.
Quick Example: Let us say you are pouring a backyard patio that is 10 feet long, 10 feet wide, and 4 inches thick. First, convert your 4 inches to feet by dividing by 12, giving you 0.33 feet. Now multiply: 10 times 10 times 0.33 equals 33 cubic feet. Divide 33 by 27, and you get exactly 1.22 cubic yards of concrete.
Quikrete and Sakrete Bag Yields
For smaller DIY jobs, Americans usually head to local hardware stores to grab bags of premixed concrete. Depending on the size of the bag you choose, here is exactly what those bags yield and how many you need for a full cubic yard:
| Common Bag Size | Approximate Yield | Bags needed per Cubic Yard |
|---|---|---|
| 80 lb Bag | 0.60 cubic feet | 45 bags per cubic yard |
| 60 lb Bag | 0.45 cubic feet | 60 bags per cubic yard |
| 50 lb Bag | 0.37 cubic feet | 73 bags per cubic yard |
Frequently Asked Questions
How do I calculate concrete yardage?
To calculate concrete yardage, multiply the length in feet by the width in feet by the depth in feet to get total cubic feet. Then divide that number by 27 because there are 27 cubic feet in one cubic yard.
How many 80lb bags of concrete are in a cubic yard?
It takes exactly 45 standard 80lb bags of premixed concrete to make one full cubic yard. If you are using 60lb bags, you will need 60 bags.
How to calculate concrete for sonotubes?
For sonotubes or fence posts, you treat the shape as a cylinder. You need the diameter in inches and the depth in feet. Our calculator automatically handles the complex pi math to give you the exact bags needed.
What is the average cost of a concrete slab in the US?
While concrete prices fluctuate by state and local suppliers, the average cost for ready mix concrete delivery in the US is between 120 and 160 dollars per cubic yard, not including the labor for finishing.