Investment Fee Drag Calculator

Investment fees compound dramatically. 1% expense ratio on 100k portfolio over 30 years at 7% gross return: 35k+ in fees vs 0.1% index fund. Compounding effect makes small fee differences enormous over time.

Run it with sensible defaults

Using portfolio value of 100,000, expense ratio of 1%, annual return of 7%, years of 30, the calculation works out to 186,876.39. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Portfolio Value, Expense Ratio %, Annual Return, and Years — do not pull with equal force. The rate and the time horizon usually dominate — compounding means a small change in either reshapes the final figure more than a similar shift in contribution size. Test this by doubling one input at a time.

How the math works

Compares portfolio growth with and without expense ratio. Difference = total fee drag.

Why investors run this

Most people's intuition for compounding is wrong — not because the math is hard, but because linear thinking doesn't account for curves. Running numbers through a calculator like this one is the cheapest way to recalibrate that intuition before making an irreversible decision about contribution rate, asset mix, or retirement age.

What this doesn't capture

Steady-rate math ignores real-world volatility. Actual returns are lumpy; sequence-of-returns risk matters most in drawdown; fees and taxes drag on compound growth; and behaviour changes in drawdowns can reduce outcomes below the projection. The number represents one scenario rather than a forecast.

Worked example

Assume a portfolio value of 250,000 with an expense ratio of 0.5%, an annual return of 6%, and a 25-year horizon.

• Portfolio with fees compounds to approximately 1,059,000
• Portfolio without fees compounds to approximately 1,073,000
• Fee drag over 25 years: 14,000 in accumulated costs

Now change only the expense ratio to 1.5%:

• Portfolio with fees compounds to approximately 998,000
• Fee drag: 75,000

The trebling of the expense ratio (0.5% to 1.5%) produces a five-fold increase in total fees paid — this is compounding at work.

When this metric matters

Fee drag becomes visible in several contexts:

• Comparing managed funds against index-tracking alternatives over multi-year periods
• Evaluating the lifetime cost of advisory fees on a growing portfolio
• Understanding the trade-off between active management and lower-cost passive holding
• Modelling retirement projections where fee assumptions differ significantly
• Assessing whether performance claims by fund managers exceed their fee burden

What the result shows and does not show

Shows: The nominal difference in portfolio value between two growth paths — one net of fees, one gross of them — and the cumulative fees extracted over the timeframe.

Does not show: Tax impact, inflation, actual sequence of returns, timing of contributions or withdrawals, fees that change over time, or whether the stated return is net or gross of all costs. Results are illustrations only, not forecasts or guarantees of future outcomes.