Compound Interest Calculator
Future value with monthly compounding, regular contributions included.
Assuming a 24% annual return, your savings reach TRY 32,810.31 after 5 years; that is TRY 22,810.31 of return on top of the TRY 10,000 you put in.
Calculation breakdown
| Total invested | ₺10.000 |
|---|---|
| Total return | ₺22.810,31 |
| Future value | ₺32.810,31 |
Compound interest means the return you earn is added to your principal and starts earning a return of its own. With simple interest the gain is calculated on the original amount every period; with compounding, each month builds on the last, so growth accelerates over time. This tool projects a starting amount — plus an optional fixed monthly contribution — to the end of the term using monthly compounding, and shows the money you put in and the return earned on top of it as separate figures.
How is it calculated?
The calculation compounds monthly:
- Periodic rate: the annual return is divided by 12 (r).
- Number of periods: the term in years is multiplied by 12 (n).
- Starting amount is carried forward with the growth factor:
principal × (1 + r)ⁿ. - Monthly contributions are assumed to be deposited at the end of each month and accumulated with the ordinary-annuity formula:
contribution × ((1 + r)ⁿ − 1) / r. If the return rate is zero, this part is simplycontribution × n. - Future value is the sum of the two parts, rounded to the kuruş.
Total return is the difference between the future value and everything you paid in (starting amount plus all contributions). The rate you enter is a gross assumption — withholding tax on deposits, fund fees and other deductions are not included.
Example
Imagine starting with a lump sum and adding a fixed amount every month. In the first months nearly all of the return comes from the principal; as time passes, the returns of earlier months start generating returns themselves and the growth curve steepens. To compare investing one lump sum versus spreading the same money over months, or to see what a few extra years of term do to the outcome, change the amounts and the term in the tool above — the compounding effect is most visible over long horizons.
Frequently asked questions
What is the difference between simple and compound interest?
With simple interest the return is calculated on the principal alone every period; with compound interest the earned return is added to the principal and earns its own return in later periods. At the same rate and term, the compound result is always higher, and the gap widens as the term grows.
What does monthly compounding mean?
It means the return is calculated and added to the balance every month; this tool divides the annual rate by 12 to get the monthly periodic rate. The same nominal annual rate produces a slightly higher effective annual return when compounded more frequently.
How are monthly contributions counted?
Each contribution is assumed to be deposited at the end of its month (an ordinary annuity). The first contribution therefore compounds for one month less than the full term and the last one earns nothing; someone who deposits at the start of each month would end up slightly higher.
Are taxes and fees included?
No. The tool works with a gross return assumption; deductions such as deposit withholding tax or fund management fees are not subtracted. To see an after-tax result, enter the rate net of deductions.
Does the result account for inflation?
No, the results are nominal; the future value does not show today's purchasing power. To see what your savings are really worth against inflation, use the inflation calculator.
What happens if I enter a zero return rate?
The future value equals the plain sum of the starting amount and the contributions, and the return shows as zero. This represents saving without any yield and is useful for isolating the effect of the contribution habit itself.
How long does it take for money to double?
The rule of 72 gives a quick estimate: divide 72 by the annual return rate to approximate the doubling time in years. For an exact answer, enter your starting amount in the tool and adjust the term until the future value reaches twice the input.