Projected scenario
Compound interest calculator
See what your money could become, one month at a time.
FINORA · Compound interest
Future balance: $170,619.05
Total contributions: $70,000.00
Interest earned: $100,619.05
Initial investment: $10,000.00
Investment period: 20 years
Monthly contribution: $250.00
Contribution timing: End of month
Tax on each month’s interest: 0%
Annual inflation: 0%
In today’s money: $170,619.05
Annual interest rate: 7%
Assumes monthly compounding and a constant rate. Advanced settings optionally include interest tax and inflation. Fees are excluded.
01Your assumptions
Display currency only; no exchange-rate conversion.
Fine-tune your plan
Illustrative monthly tax withholding, not country-specific tax treatment. Inflation changes purchasing power, not the nominal balance.
Your numbers stay in this browser.
Future balance
Balance over time
Assumes monthly compounding and a constant rate. Advanced settings optionally include interest tax and inflation. Fees are excluded.
Compare your scenarios
Add a scenario, change the inputs, then add another to compare up to three plans.
Understand your numbers
Make time part of your investment plan. Assumes monthly compounding and a constant rate. Advanced settings optionally include interest tax and inflation. Fees are excluded.
Calculation method
Bₘ = Bₘ₋₁ × [1 + r × (1 − tax)] + C
Compound interest
Compound interest means that interest becomes part of the balance used for the next calculation. This calculator divides the nominal annual rate by 12 and applies it once per month. A 6% nominal annual rate therefore means a 0.5% monthly rate; it is not the same as a 6% effective annual yield. The initial investment earns interest from the first month. Regular contributions enter at the beginning or end of each month, according to your selection.
The future balance combines your own contributions and accumulated interest. The dashed line shows what you put in; the solid line shows the resulting balance. Change one input at a time to understand its effect. A longer period gives existing interest more time to compound, but the smooth curve assumes a constant rate. Actual investments can fall in value and do not follow this curve.
For an end-of-month contribution, the monthly recurrence is B = previous balance × (1 + annual rate / 1200) + monthly contribution. For beginning-of-month contributions, add the contribution before applying interest. At zero interest, the result is simply initial capital plus all deposits. Calculations retain precision internally and round only for display; a bank that rounds each month may show a small difference.
Common questions
Does changing currency convert the amount?
Display currency only; no exchange-rate conversion.
Are my inputs stored?
Woooju Tools provides browser-based calculation estimates. Inputs are not sent to a calculation server or saved by this app. Language preference may be stored on this device. Your host may process technical access logs. No advertising or analytics scripts are active. This tool is educational and does not provide personalized financial advice.