Compound interest is interest that is computed not only on the original principal but also on the interest already earned. It is defined as the investment rate increasing exponentially. The compound interest formula is an exponential growth equation.
 
The Formula to calculate compound Interest is

$A$ = $P(1+(\frac {R}{100}))^{n}$.

$Compound\ interest$ = $A - P$

Where,

          $A$ - The original value of the investment 
          $R$ - Interest rate 
          $n$ - Total number of compounding period 
          $P$ - Value of investment

This calculator can be used for fining compound interest being calculated yearly not monthly or daily.
Months
Years
 1  $\frac {1}{12} = 0.08$ 
 2   $\frac {2}{12} = 0.17$
 3   $\frac {3}{12} = 0.25$
 4   $\frac {4}{12} = 0.33$
 5   $\frac {5}{12} = 0.42$
 6   $\frac {6}{12} = 0.50$
 7   $\frac {7}{12} = 0.58$
 8   $\frac {8}{12} = 0.67$
 9   $\frac {9}{12} = 0.75$
 10   $\frac {10}{12} = 0.83$
 11   $\frac {11}{12} = 0.92$
 12   $\frac {12}{12} = 1$

Below you could see the steps:

Step 1 :  For the known values of P and n, Compute Total Amount (A) using the formula

$A$ = $P(1+(\frac {R}{100}))^{n}$.

Step 2 : Hence calculate compound Interest using the formula

Compound Interest = A - P