Square Footage of a Rectangle Calculator

How to Calculate the Square Footage of a Rectangular Shaped Area

The area you are calculating can be many things, a wall, a floor, a backyard etc.. that is rectangle shaped and you need to get the square footage for.

That is pretty straightforward using whole numbers. It gets a bit more involved calculating from mixed numbers. However, for estimating purposes, mixed values can be rounded to whole values.

And most of the time if not always, round upwards. It is much better to overestimate than under.
Example:
for a length of 12' 6" use a 13 in your calculation.
for a width of 8' 4" use a 9 in your calculation

9 * 13 = 117 sq ft

Or you could average the values by rounding one value up and the other down.
For a length of 12' 6" use a 13 in your calculation and a width of 8' 4" use an 8 in your calculation

8 * 13 = 104 sq ft

Or if you are a stickler for precision, first convert the values to inches:

12'6" converted to inches = 150"
8' 4" converted to inches = 100"
Multiply these two values by each other to get the square inch result:

150 * 100 = 150000 square inches.

To convert this to a foot and inch result divide this amount by 144. ( there are 144 sq inches in one sq foot)

150000 / 144 = 104.16666667
the amount before the digit becomes the foot result = 104 sq ft

remove the foot amount from the decimal and you are left with 0.1666667. Next, multiply this amount by 144 to get the whole inch value. (when you took out the whole feet amount you had to divide the inches by 144. At the same time, you divided the inch value by 144 too. So it makes sense that you have to multiply this leftover decimal by the same amount of 144 to get the inch value back).

0,1666667 * 144 = 24 sq inches.
And there you have it:
12'6" * 8' 4" = 104 sq ft plus 24 sq inch

1. Convert both values to inches
2. multiply the two-inch values with each other
3. divide this result by 144 and remove the whole foot value
4. multiply the left by decimal by 144 to get the inch value

And the moral of this story, it all sounds complicated but when you get the hang of it is like falling off a roof!

And if that all sounds like to much work to you then use the calculator below!

Length One	ft in
Length Two	ft in
Rounding of Decimal	# of digits
Results:
Result in Decimal Format ft² Result ft² in²

• Construction Math - Index
• Convert Feet in Decimal Format to Foot, Inch and Fraction
• Equation Manipulation
• Calculating with Percentages
• Square Footage of a Rectangle Calculator

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