Compound Interest Calculator
Estimate how an initial investment and monthly contributions could grow. Separate money invested from compound growth.
Your numbers
Use one currency for all amounts. Changing this selector changes formatting only; it does not convert values.
Projected balance
$50,403.17- Total contributed
- $34,000.00
- Investment growth
- $16,403.17
Balance over time
| Month | Contributed | Balance | |
|---|---|---|---|
| 0 | $10,000.00 | $10,000.00 | |
| 12 | $12,400.00 | $13,065.31 | |
| 24 | $14,800.00 | $16,314.53 | |
| 36 | $17,200.00 | $19,758.71 | |
| 48 | $19,600.00 | $23,409.54 | |
| 60 | $22,000.00 | $27,279.41 | |
| 72 | $24,400.00 | $31,381.48 | |
| 84 | $26,800.00 | $35,729.68 | |
| 96 | $29,200.00 | $40,338.76 | |
| 108 | $31,600.00 | $45,224.40 | |
| 120 | $34,000.00 | $50,403.17 |
How the calculation works
The annual return is an effective annual rate, converted to an equivalent monthly rate. Contributions arrive at the end of each month. The rate stays constant; taxes, fees and inflation are excluded. A scenario is not a forecast or a guaranteed return.
Worked example
With 1,000 invested, no extra contributions and a 6% annual return, the modeled balance after 12 months is 1,060. At a 0% return, the result is simply the sum of your contributions.
Common question
Is the annual rate divided by 12?
No. An effective annual rate already includes compounding. Taking its twelfth root preserves the stated annual return. A nominal annual rate compounded monthly uses a different convention.