OmniCalcsInvestment Calculator
Project the future value of your investments with monthly additions and annual returns.
How to Use This Investment Calculator
Enter how much you have invested today, how much you add each month, your expected annual return and how long you plan to invest. The calculator projects the future value and breaks growth down year by year.
- Initial investment โ your current portfolio balance or lump sum.
- Monthly addition โ contributions made every month and reinvested.
- Annual return โ use a realistic long-term average; the market averages are lower than recent years.
- Yearly table โ shows the first 10 years (or fewer if your period is shorter).
Practical Example
Suppose you invest $10,000 now and add $300/month, earning 7% annually:
- After 10 years โ $72,000 (you contributed ~$46,000)
- After 20 years โ $180,000 (you contributed ~$82,000)
- After 30 years โ $380,000 (you contributed ~$118,000)
Notice the growth accelerates โ in the last 10 years the balance roughly doubles, purely from compounding on earlier gains.
What Your Results Mean
- Final balance โ the projected future value of your portfolio.
- Total contributed โ the actual money you put in, to compare against growth.
- Growth โ the return earned on top of contributions; the larger this is, the more compounding worked for you.
Frequently Asked Questions
What annual return should I use?
Long-term stock market averages are often quoted around 7% before inflation. For a conservative estimate use 4-6%; for planning around an aggressive stock portfolio you might use 8-10%.
Why does the yearly table show growth in dollars?
Each year the balance grows by the return on the entire balance plus your contributions. Comparing year-end values shows exactly how much the portfolio added in a given year.
How does compounding help over 20 years?
Compounding means your returns earn returns. After 20 years the growth from reinvestment typically far exceeds your total contributions, which is the core of long-term investing.
Is this a guarantee of future performance?
No. Returns vary year to year and past performance does not guarantee future results. Treat the result as a projection under the return you assume.
What if I make quarterly rather than monthly additions?
The difference is usually small. Monthly additions compound slightly faster because each contribution earns returns sooner.
Learn More
Read our in-depth guide: Compound Interest, Explained Simply โ the math powering long-term growth.