Investment Calculator
Simulate your investments and find out how much your money can grow over the years, factoring in monthly contributions and different rates of return.
The investment calculator projects how much your money can grow over the years by combining an initial amount, monthly contributions, and an annual rate of return, with earnings automatically reinvested (compound interest). It's useful for planning retirement, an emergency fund, or any long-term financial goal.
How to use
- Enter the initial amount you already have invested (can be zero).
- Enter the monthly contribution you plan to invest every month.
- Fill in the expected annual rate of return and the term in years, and watch the projection update automatically.
Worked example
Suppose you start with $5,000 and invest $500 per month at a 10% annual rate for 20 years. The total invested would be $125,000 (the initial $5,000 plus $500 × 240 months), but the accumulated amount would exceed $400,000 — meaning over $275,000 came from reinvested earnings alone. That's the power of compound interest combined with steady contributions over time.
Frequently asked questions
What rate of return should I use in the simulation?
It depends on the type of investment: fixed income tends to track close to the benchmark interest rate, while stocks have more uncertain returns that are historically higher over the long run, but with a risk of losses. Use a realistic rate for the kind of investment you're planning to make.
Do the monthly contributions also earn returns?
Yes. Each contribution becomes part of the total balance and, starting the following month, also earns returns, just like the initial amount — that's the effect of compound interest.
Does the simulation account for inflation or taxes?
No. The result shows the nominal growth of the invested amount, without deducting inflation or taxes on earnings, which vary depending on the type of investment and how long it's held.
What's the difference between this and the compound interest calculator?
Both use compound interest, but this calculator is built for recurring monthly contributions and shows separately how much you put in versus how much you earned. The Compound Interest Calculator is more general, ideal for a single lump sum or comparing one-off scenarios.
Does starting to invest earlier make a difference?
Yes, a big one. Because earnings are reinvested, each extra year lets compound interest work for longer. Starting five years earlier, even with smaller contributions, often beats someone who started later with larger ones — time is the most powerful variable in the simulation.
Can I rely on the exact figure shown?
The figure is a projection based on a fixed, constant rate, meant for planning. In practice, real returns vary month to month and can be affected by taxes, fees and inflation. Use the result as a ballpark reference, not a guarantee.