The greatest common divisor (gcd) is a number that divides two or more integers without remainder. It is used often times in fractions to find the most reduced form of a fraction. The greatest common divisor is sometimes seen in the following notation: $$ gcd(6, 9) = 3 $$ It is also reffered to as the greatest common factor (gcf), the highest common factor (hcf), or the highest common divisor (hcd). Use the calculator below to solve your gcd problems.