Compound Interest Calculator
Explore how money can grow over time through compound interest. Adjust your starting balance, annual rate, duration and compounding frequency to see an instant breakdown and year-by-year growth.
Calculate compound growth
Enter a principal amount and your assumptions. Results update as you type.
Use one currency consistently. The calculator assumes a fixed annual rate, with no additional deposits or withdrawals.
Estimated future value
Total balance after compounding1,647.011,000 compounded monthly at 5% annually for 10 years.
Illustrative calculation only. Actual rates and returns can vary.
How compound interest works
Compound interest is calculated on the original principal and on interest previously added to the balance. Over multiple periods, this can create growth on growth.
In this formula, A is future value, P is starting principal, r is the annual rate as a decimal, n is the number of compounding periods per year and t is time in years.
Example: 1,000 at 5% for 10 years
1,000 × (1 + 0.05 / 12)120 ≈ 1,647.01. The estimated interest earned is 647.01, excluding taxes, fees and other changes.
Year-by-year growth illustration
This chart uses your current inputs and shows the projected balance at selected yearly intervals. Change the calculator fields to update it.
Calculating yearly balances…
For fractional-year durations, the final row represents the selected ending time.
Compounding frequency comparison
With the same stated annual rate, more frequent compounding generally produces a slightly higher balance because interest is credited more often.
| Frequency | Periods per year | Example: 10,000 at 5% for 10 years |
|---|---|---|
| Annually | 1 | 16,288.95 |
| Quarterly | 4 | 16,436.19 |
| Monthly | 12 | 16,470.09 |
| Daily | 365 | 16,486.65 |
Compound interest versus simple interest
Simple interest is calculated on the initial principal only. Compound interest includes interest that has already been credited to the balance. For example, 1,000 at 5% for 10 years earns 500 in simple interest, while monthly compounding produces approximately 647.01 in interest.
Compare the methods with the Simple Interest Calculator.
What affects your result?
Starting amount
A larger principal generally produces a larger future value at the same rate and duration.
Interest rate
Even a small difference in the annual rate can make a noticeable difference over longer periods. This model treats the rate as constant.
Time and compounding frequency
Longer periods allow more compounding. More frequent compounding increases the number of times interest can be added under a nominal annual-rate model.
Inflation, taxes and fees
This calculator does not deduct inflation, taxes, fees, withdrawals or changes in rates. Those factors can reduce actual purchasing power or realized returns.
Frequently asked questions
How is compound interest calculated?
Future value is calculated using A = P(1 + r/n)^(nt), where the rate is expressed as a decimal.
Does this calculator include monthly contributions?
No. It calculates growth from an initial principal only. It does not add recurring deposits.
Can I calculate using AED, USD or GBP?
Yes. The calculator is currency-neutral; the results use the same currency unit as the principal you enter.
Is monthly compounding better than annual compounding?
At the same positive nominal annual rate, monthly compounding produces a slightly higher future value than annual compounding. Real account products may use different rate conventions.
Can I enter zero interest?
Yes. With a zero annual rate, the projected balance remains equal to the principal.
Does this forecast stock-market returns?
No. It is a fixed-rate mathematical illustration, not an investment forecast.
How to use the calculator
- Enter the starting principal.
- Choose an annual interest rate.
- Set the number of years.
- Select compounding frequency.
- Review the balance, interest and growth illustration.
Understanding your results
Future value: the total projected balance at the end of the chosen duration.
Interest earned: future value minus the starting principal.
Growth percentage: interest earned divided by starting principal, multiplied by 100. When principal is zero, the growth percentage is shown as zero.
Important limitations
This tool is provided for education and general planning. It assumes a fixed nominal annual interest rate, periodic compounding and no contributions or withdrawals. It does not include inflation, taxes, fees or market volatility. Results are estimates, not guarantees or personalized financial advice.
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