Free Investment Calculator 2026: Compound Interest Growth
Project your investment growth with compound interest and monthly contributions.
Discover the power of compound interest: how much you will have at the end, how much you contributed and what the returns generated.
By VOV · Last updated: October 21, 2026
How it works
How it works: monthly compounding with the entered annual rate (nominal rate divided by 12). Contributions are added at each month start. A mathematical projection, not a prediction: real markets vary and past returns don't guarantee future ones.
Use cases
- Project what you'll have in 10 years investing 500 euros monthly at 7 percent annual return
- Calculate the compound interest on your emergency fund instead of letting it sit idle at the bank
- Compare two investment funds by simulating 20,000 euros over 15 years at different rates of return
Frequently asked questions
Is compound interest realistic?
As math yes; as prediction no: the rate you enter is an assumption. Use conservative rates (4-7%) for long-term plans.
Why do monthly contributions matter?
Because time and consistency beat initial capital: with 20 years ahead, small monthly contributions become huge.
Does it account for taxes or inflation?
No: the result is gross and nominal. Subtract your tax rate and ~2-3% yearly inflation for a sense of real purchasing power.