percent Compound Interest Calculator
Calculate how money grows over time with compound interest at different frequencies.
Compound interest means you earn interest not just on your original principal, but also on the interest that's already accumulated - which is why it grows faster over time than simple interest. This calculator computes compound interest with flexible compounding frequency (annually, monthly, daily, etc.) so you can see exactly how your money grows.
Frequently asked questions
It's how often interest is calculated and added to your balance - annually, monthly, daily, etc. More frequent compounding (like daily vs. annually) results in slightly higher overall returns for the same nominal interest rate, since interest starts earning interest sooner.
Simple interest is calculated only on the original principal every period. Compound interest is calculated on the principal PLUS all previously accumulated interest, which is why it grows faster the longer the money is invested.
The same compound interest math applies to both growing savings and accruing debt - just be aware that for loans, the "growth" represents money you owe, not money you've earned.