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Concrete Footing and Slab Calculator

100% free Concrete Calculator by Four Oaks Residential


Excavated high wind zone footing with horizontal and vertical rebar installed.

How to Calculate Concrete in Cubic Yards

The Formula for Concrete Calculation

Calculating the amount of concrete you need for a project is a pretty simple task. Square or rectangular shapes are the easiest to calculate and that’s what we are going to focus on here.

Length (FT) x width (ft) x depth (ft) / 27

Notice our formula measures everything in feet. Typically footing depths and widths are measured in inches. Our calculator has a built in function to convert feet and inches where appropriate. If you are doing manual calculations, it’s pretty easy to convert feet to inches or vice versa.

Common Inch to Feet conversions in construction:

8″ = .67 ft
16″ = 1.33 ft
20″ = 1.67ft

Uses for this formula:

This mathematical formula for concrete calculation will work for footings, slabs, walkways, and driveways where the thickness is consistent.

“It's not the beauty of a building you should look at; it's the construction of the foundation that will stand the test of time.”

Simple as that.

Bookmark our page for easy access to the calculator

Memorizing all of the formulas can be tricky, especially when you are out on the job site. You don’t want to miscalculate on materials calculations, it can hurt your pockets big time. Use our calculator as many times as you want.


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