How much do fund fees actually cost over time?

Detailed Explanation

More than the headline number suggests, because the fee is charged on the whole balance every year, including on the growth that earlier years produced. A difference of a percentage point or so in expense ratio compounds in the same direction as returns do, for as long as you hold the fund. Over a multi-decade horizon that is a material share of the final balance rather than a rounding error. The practical implication is that fees are the one input you can know in advance. Returns are uncertain; the expense ratio is printed on the fact sheet.