Compound Interest Calculator

The Compound Interest Calculator can be used to compare the interest rates of different compound periods. By definition, the APR is the interest rate compounded annually. Use the Interest Calculator to determine the interest you incur in your investment or savings account.

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input interest compound   output interest compound
% = %

Compound Interest Formula


Simplified calculation
At = A0(1+r)t

where:
A0 : principal amount (initial investment)
At : amount after time t
r : annual interest rate
t : number of years


Multi-period per year compound
At = A0(1+r/n)nt

where:
A0 : principal amount (initial investment)
At : amount after time t
n : number of times the interest is compounded per year
r : annual nominal interest rate compound every 1/n year
t : number of years


Continuous compounding
At = A0ert

where:
A0 : principal amount (initial investment)
At : amount after time t
r : annual interest rate compound continuously
t : number of years