"As is right" is a phrase often used to convey that something is as it should be or is just and fair. There are multiple synonyms for this phrase, including "as it should be," "appropriately," "justly," "fairly," and "in accordance with justice." Other synonyms that may be used include "rightfully," "legitimately," "properly," and "equitably." These words all convey the same idea that something is being done or is in a certain state in a manner that is appropriate and in line with standards of fairness. Depending on the context and tone of the sentence, any of these words could be used effectively as a synonym for "as is right".