Compound Interest Calculator
Calculate compound interest for any principal, rate and compounding frequency.
About this tool
Compound interest grows a principal amount by adding interest not just on the original sum but on interest already earned. This calculator shows the final balance and total interest earned for any principal, rate, compounding frequency and time period.
Key Features
- Choice of 5 compounding frequencies
- Final balance and total interest
- Works for any time period, including fractional years
How to Use
- Enter your principal amount.
- Enter the annual interest rate.
- Choose how often interest compounds.
- Enter the time period in years and click Calculate.
Benefits
- Compare savings accounts or investments with different compounding
- Understand how compounding frequency affects growth
- Plan long-term savings targets
Frequently Asked Questions
More frequent compounding (daily vs. annually) earns slightly more, because interest starts earning its own interest sooner — the difference grows with a higher rate and a longer time period.
The math is identical either way — it tells you the total balance after compounding, whether that balance is money you've saved or money you owe.