2 Answers

Bob/PKB

Karma: 945575

courtesy of ONLINE CONVERSION

The formula for Square feet is:
length × width

The formula for Cubic feet is:
length × width × height

Since we know the Square feet of the garden, we now have the conversion to Cubic feet:
(cubic feet) = (square feet) × (height in feet)

So.... If you wanted the topsoil to be 3 inches thick, you would need:
12 × 0.25 = 3
You would need 3 cubic feet of topsoil.

Notice that I convert 3 inches to 0.25 feet before using the formula. All the measurements must be in the same units for it to work. And it will work for anything. Meters, feet, inches, just as long as all are the same.

Once again, here is the formula:
(cubic feet) = (square feet) × (height in feet)

Or for meters:
(cubic meters) = (square meters) × (height in meters)

13 years ago. Rating: 1
Comment this answer

Dama

Sorry, uncertain where the 12 comes from?
I have a total of 4,961 sq.ft. of yard area; consisting of many small to larger measurable areas. And I wish to know how to calculate the number of cubic yards (of arbor mulch) required to cover the 4,961 sq.ft. with 1 1/2 inches of mulch?
Thanks,
Dama

commented 13 years ago

Bob/PKB

12 represents the number of inches in a foot.
Square feet (4961) x .0125 = amount of cubic feet of mulch you need.
In the example, which I didn't copy in its entirety, and I apologize, there was 12 square feet of garden needing topsoil.
Your garden specialist can convert the cubic feet to yards for you.

commented 13 years ago

jenp

Karma: 28635

Calculating cubic feet from square feet is impossible since the two are not the same measurement: cubic feet is of volume, whereas square feet is of area.