Interest Calculator
Calculate simple or compound interest on any principal amount.
Final balance
$16,470
Interest earned
$6,470
Growth
64.7%
Simple vs. compound
Simple interest is charged only on the original principal — 5% on $10,000 earns the same $500 every year. Compound interest is charged on the running balance, so each year's interest itself earns interest. Over a decade the difference is substantial: $10,000 at 5% earns $5,000 simple but about $6,470 compounded monthly.
Where each applies
Most savings accounts, credit cards, and mortgages compound. Simple interest survives in some auto loans, short-term personal loans, and bonds' coupon payments. When comparing offers, always check the compounding frequency behind the quoted rate.
Frequently asked questions
- How does the Interest Calculator work?
- Calculate simple or compound interest on any principal amount.
- Is the Interest Calculator free to use?
- Yes. The Interest Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
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