How It Works
The calculator compounds the assumed annual rate monthly and adds contributions at the end of each month.
The result separates your contributions from projected growth so you can see the effect of compounding.
Future value is the amount the starting balance and recurring contributions would become under the assumed monthly compounding rate. The calculator separates the amount you contributed from the projected investment growth.
The projection assumes a constant return and regular end-of-month contributions, so it is useful for illustrating compounding rather than forecasting actual market performance.
Formula
- P — Starting amount
- C — Monthly contribution
- r — Monthly rate
- n — Number of months
Example
Example inputs: Starting $5,000, $300/month, 7% annual return, 20 years.
Result: Projected value is approximately $166,000 under the stated constant-return assumption.
Frequently Asked Questions
Is this guaranteed?
No. Investment returns fluctuate, and a constant rate is only an illustrative assumption.
What is the difference between future value and compound interest?
Future value is the ending amount after growth and contributions. Compound interest describes the process by which prior interest or investment gains can themselves generate additional growth.
Does inflation reduce the future value shown?
The displayed result is a nominal amount based on the rate you enter. It does not automatically adjust the result for inflation or show purchasing power in today's dollars.
This calculator provides estimates for informational purposes only and should not be considered financial, tax, or legal advice.