fixed cost vs fixed charge

fixed cost and fixed charge both are nouns.

Word	Noun	Adjective	Verb	Adverb
fixed cost	Yes	No	No	No
fixed charge	Yes	No	No	No

As nouns, fixed cost and fixed charge are synonyms defined as:

fixed cost and fixed charge: a periodic charge that does not vary with business volume (as insurance or rent or mortgage payments etc.)

Other synonyms of fixed cost include fixed costs.

fixed cost (noun)	fixed charge (noun)
a periodic charge that does not vary with business volume (as insurance or rent or mortgage payments etc.)	a periodic charge that does not vary with business volume (as insurance or rent or mortgage payments etc.)