ETF investment growth accounting for expense ratio fee drag

Fund growth with fee drag: how this calculator works

This calculator projects the future value of a fund-based investment (ETF, index fund, mutual fund, SIP, or any diversified pooled investment) given an initial balance, ongoing monthly contributions, an expected annual return, and an expense ratio. The expense ratio is subtracted from gross return before compounding — the same math that applies whether the product is branded as an ETF, index fund, or mutual fund.

Why fees compound against you

A 0.1% expense ratio versus a 1.5% expense ratio looks small in year one but compounds into a large delta over decades. On a 100,000 starting balance growing at 7% gross for 20 years, a 0.1% fee leaves 372,756. A 1.5% fee leaves 288,636. That is 84,000 of compounded fee drag — money that never reaches the investor. Use this tool to run your own numbers.

How to use it for different product types

Index fund: set expense ratio to the fund prospectus number (commonly 0.03% to 0.20%). ETF: same — ETFs publish an expense ratio in the fact sheet. Mutual fund: expense ratios are usually higher (0.5% to 2%+) and may include load fees not captured here. Monthly SIP: set initial to 0 and contribute only monthly. The underlying math is the same across all four product framings; the calculator is product-agnostic.

What this tool does not model

Transaction costs (bid-ask spread, brokerage commissions), tax drag on distributions, front-end or back-end loads, currency hedging costs on foreign-listed products, and tracking error between an index and the fund tracking it. It also assumes the return and expense ratio are stable across the holding period — in practice both vary. Use the result as a projection, not a prediction.

Worked example

Starting balance 10,000. Monthly contribution 500. Expected annual return 8%. Expense ratio 0.1%. Over 20 years that grows to approximately 339,176. Raise the expense ratio to 1% and the same inputs produce closer to 295,000 — a 44,000 penalty from the fee difference.