401k Retirement Planner

Investment balances remain separate from tax-aware paycheck estimates. Confirm plan terms before using an election. Compares a 0.1 percentage-point grid plus current, full-match and statutory-cap boundaries under the entered return, fee and tax assumptions. This is a sampled comparison, not a global optimum or plan guarantee. Optional affordability constraint. Cost uses the selected current income-tax rate and confirmed first-year pre-tax/Roth split; payroll taxes and other deductions are not recalculated. Optional, from 0 through 100. Blank means ownership is unknown. The opening balance is assumed already owned; future employer contributions follow this fixed vesting assumption. Paycheck figures are equivalents from the 12-month ledger, not a dated payroll calendar. Affordability checks the highest modeled monthly net-pay reduction scaled by 12 divided by the selected annual pay frequency; late Roth catch-up months can cost more than the annual average. Vesting is unconfirmed; the account projection includes employer contributions before vesting. Optional separate age for the catch-up test. If blank, the projection explicitly assumes your current age is the year-end age; enter it if your birthday changes the applicable tier.

Compound growth is not linear — it accelerates over time because each year's gains generate their own gains in subsequent years. A 25-year-old contributing $6,000 per year at 7% growth will accumulate roughly $1.2 million by age 65, while a 35-year-old making identical contributions reaches only about $567,000 — less than half. That single extra decade of compounding is worth more than all the contributions the 35-year-old will ever make. Starting at 22 instead of 30 adds eight years of compounding that are mathematically irreplaceable. If you started late and are feeling behind, the most effective responses are: maximize contributions immediately, use catch-up contributions (an extra $8,000 in 2026 if you are 50 or older), delay retirement by even one or two years to extend the compounding runway, and consider working with a fee-only financial planner to optimize what is left. The damage from delay is real, but it is never too late to close the gap meaningfully.

Tax comparison is a simplified all-pre-tax versus all-Roth illustration. Required Roth catch-up, future wage tests, withdrawals and complete tax returns can change actual results; no election winner is certified. Optional affordability constraint. Cost uses the selected current income-tax rate and confirmed first-year pre-tax/Roth split; payroll taxes and other deductions are not recalculated. Use prior-calendar-year plan-sponsor FICA wages. No prior FICA wages and special employer aggregation or non-FICA rules require the corresponding selection; current salary and household income do not replace this fact. Catch-up room depends on age attained by calendar-year end and the plan’s supported election rules. The 2026 Roth test uses prior-year plan-sponsor FICA wages strictly above USD 150,000; it changes catch-up tax treatment, not the age-based contribution ceiling. Unknown or special rules keep the tax estimate unconfirmed while the investment projection remains labeled as potential contribution room. Withdrawal-rate income is a pre-tax illustration, not guaranteed income or a complete retirement tax calculation. For 2026, the employee base limit is USD 24,500; eligible catch-up is USD 8,000 at year-end ages 50–59 or 64+, and USD 11,250 at ages 60–63. Thus supported total ceilings are USD 32,500 or USD 35,750, subject to compensation and plan rules. Future projection years use the selected limits as frozen assumptions, not newly enacted official amounts.

Investment fees are the silent destroyers of retirement wealth because they compound against you in the same way that investment returns compound for you. Every dollar paid in expense ratios is a dollar that does not grow over the remaining decades of your career. The expense ratio is the annual percentage of assets deducted by the fund manager for administration and investment management. A 0.1% index fund and a 1.0% actively managed fund might sound nearly identical, but over a 30-year career the difference typically exceeds $200,000 on a $500,000 balance — enough to fully fund several years of retirement. Research consistently shows that most actively managed funds underperform low-cost index funds after fees over long time horizons. When evaluating your 401(k) fund options, sort by expense ratio first, then choose the lowest-cost fund in each asset class you want. If your plan only offers high-fee funds, contribute enough to capture the full employer match, then direct additional savings to a low-cost IRA before returning to the 401(k). To plan multi-year contributions ahead of time, check our projected 2027 401(k) Limits guide.