Comprehensive Guide
Learn more in our Investing Guide.
How it works
An expense ratio is a quiet annual tax on your entire balance — charged automatically, invisible on statements, and devastating specifically because it compounds. A target-date fund charging 0.55% against a 0.08% DIY equivalent looks like pocket change: forty-seven hundredths of a percent. Run the compounding and the framing collapses. On $100,000 growing at 7% gross with $12,000 added yearly, that gap strips roughly $118,000 from the ending balance across twenty-five years — money that bought nothing visible and returned nothing ever. The mechanism deserves respect: fees shave EVERY year's returns BEFORE compounding applies, so each shaved dollar also forfeits every subsequent year of growth it would have earned, which is why the gap curve accelerates — small at year five, serious at fifteen, staggering at thirty. This calculator plots that acceleration checkpoint by checkpoint. Fairness requires noting what TDF fees buy: automatic rebalancing and a professionally managed glidepath, genuinely valuable for hands-off savers. The rational comparison is therefore not TDF-versus-nothing but expensive-TDF-versus-cheapest-suitable-TDF, where basis points remain pure giveaway.Formula
Net return = gross return − expense ratio | Ending = FV(balance, net rate, years) + FV of contributions | Drag = cheap ending − TDF ending
Tips
- Compare share classes — the same TDF family often charges wildly different fees.
- Inside 401(k)s, check whether a cheaper index TDF sits alongside the default option.
- Past roughly 15-year horizons, fee gaps dominate almost any selection nuance.
- Do not abandon the TDF glidepath for a slightly cheaper mix you will never maintain.
- Recheck ratios annually — fee compression keeps improving the cheapest options.