round out vs round down

round out and round down both are verbs.

Word	Noun	Adjective	Verb	Adverb
round out	No	No	Yes	No
round down	No	No	Yes	No

As verbs, round out and round down are synonyms defined as:

Other synonyms of round out include round, round off.

round out (verb)	round down (verb)
make bigger or better or more complete	express as a round number
make round
express as a round number
fill out