US Standard Area
These are the most common measurements:
 Square Inch
 Square Foot
 Square Yard
 Acre
 Square Mile

Small surfaces are usually measured in square inches, rooms and buildings in square feet, carpet in square yards, property in acres, and territory in square miles
Square Inch
Area is length by length, so a square inch is a square that is 1 inch on each side.
The Unit is inch × inch, which can be written many ways, such as
 in^{2}
 inch^{2}
 sq in
 sq inch
 square inch
 etc ...
Square Foot
A square foot is a square that is 1 foot on each side.
The Unit is foot × foot, which can be written many ways, such as
 ft^{2}
 foot^{2}
 sq ft
 sq foot
 sq feet
 etc ...
Acre
One acre is equal to 43,560 square feet
Square Mile
A square mile is a square that is 1 mile on each side.
More Examples
A square inch is about:
An acre is:
 4,840 square yards
 43,560 square feet
 a square with sides 208.71 feet, or 69.7 yards
 about 0.4 hectare (40% of the area of a hectare)
A square mile is:
