Compound Interest Calculator – Calculate Your Investment Growth
Calculate compound interest, future value, total contributions, and investment growth in seconds.
Calculate Your Investment
Your Results
Results are estimates. Actual investment returns may vary because of taxes, fees, inflation, market performance, and contribution timing.
About the Compound Interest Calculator
A compound interest calculator estimates how money can grow when interest is added to the existing balance and subsequently earns additional interest. It can be used for savings, investments, retirement planning, education funds, and long-term financial goals.
Initial Investment
The amount of money deposited or invested at the beginning.
Interest Rate
The annual percentage rate used to calculate investment growth.
Compounding Frequency
Determines how often interest is calculated and added to the balance.
Investment Period
The amount of time the money remains invested.
Additional Contributions
Regular contributions added during the investment period.
Future Value
The estimated total value of the investment at the end of the period.
Compound Interest Formulas
The calculator uses standard compound-interest equations. The mathematical formula depends on whether additional contributions are included.
1. Compound Interest Without Contributions
Where A is the future value, P is the principal, r is the annual interest rate, n is the number of compounding periods per year, and t is time in years.
2. Compound Interest With Regular Contributions
Here PMT represents the regular contribution made at each compounding period.
3. Interest Earned
4. Total Contributions
Step-by-Step Compound Interest Calculation
Suppose you invest $10,000 at 8% annual interest, contribute $500 every month, and leave the money invested for 10 years with monthly compounding.
Calculation History
Your recent calculations are stored locally in your browser. They are not sent to a server.
| Date | Initial | Contribution | Rate | Years | Future Value |
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Frequently Asked Questions
What is compound interest?
Compound interest is interest calculated on both the original principal and previously accumulated interest.
How does compound interest grow money?
As interest is added to the balance, future interest can be earned on that larger balance. Over long periods, this can produce exponential-style growth.
What is the compound interest formula?
For a lump-sum investment, the standard formula is A = P × (1 + r/n)^(nt), where P is principal, r is the annual rate, n is the compounding frequency, and t is time in years.
Is monthly compounding better than annual compounding?
If the nominal annual interest rate is the same, more frequent compounding generally produces a slightly higher effective return, assuming all other conditions remain equal.
Does this calculator include regular investments?
Yes. You can enter an additional contribution and the calculator estimates its effect on the final value.
Is compound interest guaranteed?
No. This calculator provides a mathematical estimate based on the interest rate you enter. Actual investment returns can fluctuate, and fees, taxes, inflation, and market conditions can affect results.
What is the difference between simple and compound interest?
Simple interest is generally calculated only on the original principal, while compound interest calculates interest on the principal plus previously accumulated interest.