square foot vs sq ft

square foot and sq ft both are nouns.

Word	Noun	Adjective	Verb	Adverb
square foot	Yes	No	No	No
sq ft	Yes	No	No	No

As nouns, square foot and sq ft are synonyms defined as:

square foot and sq ft: a unit of area equal to one foot by one foot square

square foot (noun)	sq ft (noun)
a unit of area equal to one foot by one foot square	a unit of area equal to one foot by one foot square