Compound Interest Calculator
Calculate compound interest with any compounding frequency.
The power of compounding
Compound interest earns interest on your interest. The more frequently it compounds (monthly beats annually), and the longer it runs, the faster your money grows — Einstein reputedly called it the eighth wonder of the world.
The formula
A = P × (1 + r/n)^(n×t), where P is principal, r is the annual rate, n is compounding periods per year, and t is years.
Frequently asked questions
Does frequency really matter?
Yes, but with diminishing returns. Monthly vs annual compounding at 8% over 10 years differs by a few percent of the final amount — the rate and time matter far more.