Investment calculator
Compare how two annual investment fees can change the long-term value of the same portfolio plan. The model uses transparent constant-return assumptions, not historical market data.
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The same starting investment, monthly contribution and gross annual return are used for both plans. Each annual fee reduces the annual growth factor before it is converted to an equivalent monthly factor. Monthly contributions are added at the start of each modeled month.
The no-fee benchmark is a mathematical reference using the same assumptions with a 0% annual fee. “Ending-value drag” is the shortfall versus that benchmark; it combines fees and the compounding those deducted amounts no longer receive, so it is not the same as a statement of fees directly paid.
Why fees compound
Investment fees reduce the amount of the portfolio that remains available to compound. The long-term cost therefore includes both the fee effect itself and the future growth that the deducted amount can no longer earn.
(1 + gross return) × (1 − annual fee)
net annual factor^(1/12)
Monthly contribution added at the start of each modeled month
Same plan and return assumption with annual fee = 0%
How to use it
Keep the investment amount, contribution schedule, return assumption and horizon identical. Change only the annual fee to isolate the modelled effect of cost.
This can be useful when comparing two funds, model portfolios or platforms whose annual percentage costs differ, as long as you remember that real products can also differ in holdings, tracking, taxes, transaction costs and performance.
Interpreting fee drag
Finance Charts defines ending-value drag as the difference between a fee-bearing projection and the same projection with a 0% annual fee. Because the lower balance also earns less growth later, that difference includes lost compounding as well as the effect of the annual fee.
Frequently asked questions
It accepts an annual percentage fee such as an expense ratio or comparable ongoing annual cost. It does not read a live fund fee or product document for you.
This model combines the gross annual return factor with the annual fee factor multiplicatively: (1 + return) × (1 − fee). That is then converted to an equivalent monthly growth factor.
No. Taxes, bid-ask spreads, commissions and other costs are not included unless they are represented by the annual fee input itself.
Because money removed by ongoing costs is no longer present to compound in later periods. Over long horizons, that lost growth can become material.
Yes. The calculator stores the current assumptions in the URL so the Copy share link button can reopen the same scenario.