Treat the result as a comparison scenario, not a forecast. Real returns vary, losses occur, and fees and taxes depend on the investment and account.
Return and contribution assumptions
The expected return is an input, not a prediction. A constant annual rate makes scenarios comparable but does not represent the path of real markets.
Recurring contributions can have a large effect because each deposit adds principal and then has time to compound. Change one input at a time to compare time, contribution, and return assumptions.
- Use conservative assumptions for planning.
- Compare more than one return scenario.
- Consider inflation when interpreting future purchasing power.
Why fees matter
Investment fees reduce the amount left to compound. Even a small annual percentage can create a noticeable long-term difference because the fee affects both current assets and future growth.
The fee-impact figure is a simplified comparison between the entered gross return and the return reduced by the entered annual fee rate. It does not reproduce a fund's exact daily expense calculation.
Important limits
The calculator excludes taxes, contribution limits, employer matches, withdrawals, changing returns, and sequence-of-returns risk. It also assumes the annual fee is a simple reduction in return.
No result identifies a suitable investment or guarantees that an entered return can be achieved.
The formula used
FV = P(1 + r/12)^(12t) + PMT × [((1 + r/12)^(12t) − 1) ÷ (r/12)]The net annual rate r is the entered expected return minus the entered annual fee rate. Contributions are modeled at the end of each month.
Example: investing for 20 years
Starting with $10,000, adding $500 per month, and assuming a 7% annual return with 0.25% annual fees produces a long-term mathematical projection. The calculator separates the $130,000 contributed from estimated growth and compares the result with a no-fee version of the same assumption.
Sources and further reading
We use primary educational sources to check terminology and explain how the calculation fits into real financial decisions.
Investor.gov — Compound Interest Calculator↗Investor.gov — How fees and expenses affect your portfolio↗