Why a 0.8% fee difference becomes six figures
Fees are charged on your whole balance every year, so they act like a permanent reduction in your return — and the loss compounds, because every dollar taken in fees also stops growing. A $50,000 balance with $10,000/year added, earning 7% for 25 years, ends near $904,000 at a 0.05% fee but only about $780,000 at 0.85%. That ~$124,000 gap is the fee iceberg: the visible fees are small, the lost compounding is not.
How to find your actual fees
Check three layers: each fund's expense ratio (in the plan's fund lineup or the fund fact sheet), plan administration fees (in the annual 404(a)(5) fee disclosure your provider must send), and any advisor wrap fee. Total all-in costs under 0.5% are good; over 1% deserves action. The fix is usually just moving money into the cheapest broad index funds on your plan's menu — nearly every plan has at least one.
When higher fees are (and aren't) worth it
Paying 0.1-0.2% more for a fund that matches your needs is trivial. Paying 1%+ for active management is statistically a bad bet: most active funds trail their index over 15 years, and the ones that will beat it aren't identifiable in advance. The employer match changes nothing about fund choice — take the match, then choose the cheapest diversified options inside the plan.
How to use this calculator
Pull two numbers from your plan's fund lineup: the expense ratio of the fund you're currently in (often a default target-date or actively managed fund) and the cheapest broad-market index fund your plan offers. Enter your current balance, your annual contribution including any employer match, an expected return, and the years until you retire. The gap the calculator shows is money that leaves your account for no added benefit — index funds track the same markets the expensive funds try, and usually fail, to beat. If the difference surprises you, the fix takes about ten minutes: reallocate future contributions and existing balances into the low-cost option on the same menu.