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Calculate how your money grows over time with compound interest. See total earnings, year-by-year breakdown, and the Rule of 72.
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods, causing your money to grow exponentially over time.
after 10 years
Regular contributions are added at the end of each compounding period.
Compound interest is calculated using the formula:
A = P(1 + r/n)ntA = Final amount
P = Principal (initial investment)
r = Annual interest rate (decimal)
n = Compounding frequency per year
t = Time in years
Formula
A = P(1 + r/n)^(nt)A = the final balance, principal plus all accumulated interest
P = the starting principal
r = the annual interest rate written as a decimal, so 7% is 0.07
n = how many times interest is compounded per year
t = the number of years
Worked Example
$10,000 at 7% compounded monthly for 10 years
Did you know? The Rule of 72 estimates a doubling time by dividing 72 by the annual rate. At 7% it predicts 10.29 years against an exact 10.24, so a shortcut you can do in your head lands within three weeks of the real answer over a decade.
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