About the Investment Calculator
An investment calculator projects the future value of savings that earn compound interest. Enter a starting amount, a monthly contribution, an expected annual return and the number of years, and it shows what your investment could grow to, how much you contributed, and how much is growth (interest).
How Investment Calculator works
With monthly compounding the future value is:
FV = P(1+r)n + PMT · ((1+r)n − 1) ÷ r
where P = initial amount, PMT = monthly contribution, r = monthly return (annual ÷ 12), n = months.
Example: ,000 start + 0/month at 7% for 20 years ≈ 8,000, of which about ,000 is contributions and ,000 is growth.
Common uses
- Project retirement or long-term savings
- See the power of compounding over time
- Compare contribution amounts or return rates
- Set a savings goal and work backwards
Frequently asked questions
What is compound interest?
Interest earned on both your original money and the interest already added — so it grows faster over time.
What return rate should I use?
Historically the stock market has averaged roughly 7% per year after inflation, but returns vary and are not guaranteed.
Does it account for inflation or tax?
No — it shows nominal growth before inflation and taxes. Use a lower 'real' rate to estimate inflation-adjusted value.