Investment fee drag calculator
A fund’s expense ratio is a permanent drag on your compounding, not a one-off charge. Compare two fees and see the compounding gap — the dollars, and the share of your final wealth, you give up to fees over the years.
Why a small fee costs so much
An expense ratio is charged every year on your whole balance, and the money it takes would otherwise have stayed invested and compounded. So the true cost isn’t the fee itself — it’s the fee plus all the growth that fee would have earned for the rest of your horizon. That’s why a gap of less than one percent a year can swallow a fifth or more of your final wealth over decades.
The math is simple: your fee lowers the return you actually keep, and that lower net return is compounded.
net return = gross return − expense ratio, then compounded over N years
This tool compounds the same starting balance and contributions twice — once at each expense ratio — and the difference is what fees cost you. It assumes a constant gross return and monthly compounding, and ignores taxes, trading costs and any performance difference between the funds. Real markets don’t return the same amount every year, so treat the result as an illustration of the shape of fee drag, not a prediction. For the flip side — how reinvested returns compound in your favour — see the compound return calculator and the dividend reinvestment calculator.
Illustrative math on the numbers and fee assumptions you enter — not a forecast, a fund recommendation, or financial advice. No live prices or fund data are used. Your figures never leave the page — the calculation runs entirely in your browser. The page loads standard pageview analytics, which never sees your numbers.
This math stops at what you typed in.
Tradune runs it continuously on your real holdings — with your money-weighted return next to a buy-and-hold SPY twin, and SEC insider filings flagged on the stocks you own.
Educational analytics — not investment advice.