What is diameter of 24 inch circumference?

7.64 inches. Note that the calculation for circumference is 2*pi*r Rearranging C=2*pi*r, we get 2*r = C / pi Since 2*r = diameter, we can say that D = C / pi Since we know that C = 24 and pi = 3.14159265, we can calculate that: D = 24 / 3.14159265 = 7.63943727