How would the acceleration of gravity near earths surface change?

In general, when near the Earth's surface, scientists use 9.8 meters per seond^2 since the slight difference in elevation along the Earth's surface doesn't affect the acceleration very much. But if you want the exact formula it is: (G(msub1)(msub2))/radius^2. msub1 and msub2 are the masses of the two objects, and G is 6.67x10^(-11), the gravitational constant.