Get yardage
We convert feet and inches into cubic feet and cubic yards automatically.
FREE CONCRETE CALCULATOR
How much concrete do you need?
Calculate cubic yards, cubic feet and bag counts for slabs, patios, driveways, post holes and round footings. Add a waste buffer and compare bags with ready-mix.
Calculate concrete →LENGTH × WIDTH × DEPTH
One calculator. Multiple project types. No signup.
PROJECT CALCULATOR
Enter your measurements
YOUR ESTIMATE
Concrete slab
ORDER APPROX.—cubic yards
WITH WASTE—cubic feet
BEFORE WASTE—cubic feet
Bagged concrete estimate
40 lb—bags
50 lb—bags
60 lb—bags
POPULAR80 lb—bags
90 lb—bags
Bags or ready-mix?
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WHY THIS TOOL
Volume is only the first answer. You need to know what to buy.
Compare bag sizes
See approximate 40-, 50-, 60-, 80- and 90-lb bag counts in one place.
Compare buying options
Enter your local bag and ready-mix prices to compare material cost before delivery and labor.
PROJECT CALCULATORS
Start with the job you're pouring.
Concrete Slab Calculator →Slabs, floors and pads
Driveway Calculator →Driveway yardage and bags
Patio Calculator →Patio concrete estimate
Post Hole Calculator →Fence and deck posts
80-lb Bag Calculator →How many bags to buy
Bags per Yard →Quick bag conversion guide
Concrete Cost Calculator →Estimate material cost
Garage Slab Calculator →Garage floor yardage
Sidewalk Calculator →Walkway yardage and bags
Shed Slab Calculator →Concrete pads for sheds
Footing Calculator →Continuous footing volume
Sonotube Calculator →Round pier concrete
Concrete Truck Calculator →Estimate ready-mix loads
Concrete calculator FAQ
How is cubic yardage calculated?
For a rectangular pour, multiply length × width × thickness in feet to get cubic feet, then divide by 27 for cubic yards.
Why add a waste buffer?
Real pours can include uneven excavation, spillage and measurement variation. The calculator defaults to 10%, but you can change it.
How many 80-lb bags equal one cubic yard?
Using an approximate 0.60 cubic-foot yield per 80-lb bag, one cubic yard is about 45 bags before any additional buffer.