Formulae for the various compound interest calculations...
Interest = Principal(1+(Rate/100))n Annual
Interest = Principal(1+(Rate/200))2n Semi-Annual
Interest = Principal(1+(Rate/400))4n Quarterly
Interest = Principal(1+(Rate/100))years * (1+(fraction(Rate/100))) Annual and fraction
Interest = Principal(1+(Rate1/100))*(1+(Rate2/100))*(1+(Rate3/100)) Different Annual Rate