Compound Interest Calculator

Enter any three of the four values below — principal, rate, time, and total accrued amount — and the one you leave out is calculated automatically using the compound interest formula:

$A equals P times open paren 1 plus r over n close paren, raised to the power n t$

Principal (P)

Total principal amount, if known

Rate (R)

Interest rate, % per year

Compound (n)

Time (t)

Time period, based on the selection above

Total Amount (A)

Total (principal + interest)

What do the symbols mean?

A	Total accrued amount, i.e. principal + interest
P	Principal amount
I	Interest amount
R	Annual nominal interest rate, in percent
r	Rate of interest per year, r = R / 100
t	Time period involved, in years (the calculation period)
n	Number of compounding periods per year

A Special Case: Continuous Compounding

As the number of compounding periods per year (n) grows toward infinity, the compound interest formula converges to a simpler one built around Euler's number (e):