Expense Ratio Calculator

Compare how an annual expense ratio could affect long-term investment value. Enter a starting amount, monthly contribution, gross return, expense ratio and period to see projections with and without the expense ratio, the estimated value difference and a yearly table.

Finance Runs client-side Free to use

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About the Expense Ratio Calculator

Expense Ratio Calculator illustrates how a fund’s annual expense ratio could affect the value of an investment over time. It runs two projections from the same starting investment, monthly contribution, gross annual return and period: one with no expense ratio and one with your expense ratio applied.

The net return is calculated as (1 + gross return) ÷ (1 + expense ratio) − 1. Both projections compound monthly at the matching monthly rate with contributions added at the end of each month. The results show both final values, the estimated long-term value difference, total contributions and a year-by-year table. This is a simplified illustration: real fund fees, taxes, transaction costs, cash flows and returns can differ, and the difference is not the amount of fees actually charged.

How to use

Enter the starting investment and monthly contribution.
Enter the gross annual return you want to assume and the expense ratio.
Enter the investment period in whole years.
Click Calculate to compare the two projections.
Copy or download the summary, or download the yearly table as CSV.

Key features

Side-by-side projections with and without the expense ratio.
Documented net-return formula and monthly compounding.
End-of-month contributions in both projections.
Estimated long-term value difference and total contributions.
Year-by-year comparison table with CSV download.
Display-only currency symbol.
Copy Summary, Download Summary, Reset and Back.

Best practices

Use the expense ratio published in the fund’s own documents.
Try several return assumptions; the difference depends heavily on them.
Consider other costs such as taxes, exit loads and transaction costs.
Compare funds on objectives and risk as well as cost.
Use the result as an illustration, not a forecast.

Benefits

Makes small percentage differences visible over long periods.
Transparent method with every formula shown.
Helps frame questions to ask about fund costs.
Private: nothing is uploaded or stored.

Frequently asked questions

How is the net return calculated?

Net return = (1 + gross return) ÷ (1 + expense ratio) − 1. For a 10% gross return and a 1% expense ratio, that is 1.10 ÷ 1.01 − 1 ≈ 8.91%.

Why not just subtract the expense ratio from the return?

Subtracting gives a close but slightly different figure. The division method treats the expense ratio as a proportion of the fund value, which is the documented method this tool uses.

Is the value difference the fees I would pay?

No. It is the estimated difference in final value between the two projections, which includes the growth that money would have earned. Actual fees are charged differently and can vary.

How does monthly compounding work here?

Each annual rate is converted to a monthly rate of (1 + annual rate)^(1/12) − 1. Each month the balance grows by that rate and the monthly contribution is added at the end of the month.

Are taxes and other costs included?

No. Taxes, exit loads, transaction costs and changes in returns are not modelled. Real results can be different.

Does this recommend a fund?

No. It only compares two projections from the numbers you enter. It does not rate or recommend any fund.

Is my information saved or sent anywhere?

No. Every calculation runs in your browser. The numbers you enter and the results are not uploaded, not looked up online and not saved in browser storage. Reset clears them from the page.