Compound Interest Calculator 📈
Calculate compound interest and see how your investment grows over time. Enter principal, annual rate, compounding frequency, and years — all in your browser, instant results.
About the Compound Interest Calculator
This compound interest calculator runs entirely in your browser. Enter the principal, annual interest rate, compounding frequency, and number of years to estimate the final value of your investment. Nothing is uploaded to a server — all calculations happen instantly with JavaScript on your device.
How the calculation works
The calculator uses the standard compound interest formula:
A = P × (1 + r/n)n×t
Where P is the principal, r is the annual interest rate (as a decimal, e.g. 5% becomes 0.05), n is the number of times interest is compounded per year, and t is the number of years. The interest earned is A − P. Common compounding frequencies: 1 = annually, 2 = semi-annually, 4 = quarterly, 12 = monthly, 365 = daily.
Frequently asked questions
Does this tool upload my data? No. All calculations happen locally in your browser. Your inputs never leave your device.
What is compounding frequency? It is how often interest is added back to the principal each year. More frequent compounding produces a slightly higher final amount because you earn interest on interest sooner.
Does it support regular contributions? This version calculates a single lump-sum investment. For recurring monthly deposits, split the calculation into segments or use a dedicated savings calculator.
Can I use a different currency? Yes. The numbers are unit-agnostic — enter values in any currency and the result will be in the same currency.