Ratio

The relation which one quantity or magnitude has to another of the same kind. It is expressed by the quotient of the division of the first by the second; thus, the ratio of 3 to 6 is expressed by / or /; of a to b by a/b; or (less commonly) the second term is made the dividend; as, a:b = b/a.

Hence, fixed relation of number, quantity, or degree; rate; proportion; as, the ratio of representation in Congress.

The relationship between two numbers or amounts

the relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree; "an inordinate proportion of the book is given over to quotations"; "a dry martini has a large proportion of gin"