401k Calculator

Each projection year is built from two separate deposits — yours and your employer’s — and they obey different rules. Your side starts as your contribution percentage times eligible compensation, where eligible compensation is your salary capped at the 2026 IRS limit of $360,000. That desired amount is then trimmed to the elective-deferral ceiling: $24,500 for 2026, plus a catch-up if you qualify. The catch-up is $8,000 once you are 50 or older at calendar year end, and rises to $11,250 in any year you turn 60, 61, 62 or 63 — then drops back to $8,000 at 64. The model checks your age at the end of each projected year, so those four elevated years appear and disappear automatically in the schedule. The employer match is the part worth reading twice. It is defined by two numbers: cents per employee dollar, and the slice of salary those matched dollars can come from. "100% on the first 6%" means you enter 100 and 6. The calculation multiplies eligible compensation by the match limit percentage to get a matchable salary figure, takes the smaller of your actual deferral and that figure, and applies the cents-per-dollar rate to it. That "take the smaller" step is the cliff. On a $75,000 salary with a 100%-on-6% formula, going from 5% to 6% of salary adds $750 of your money and $750 of your employer’s — an instant 100% return. Going from 6% to 20% adds $10,500 of your money and exactly zero employer dollars. The match is already maxed; nothing above the match cap changes it. Contributing past 6% is still often sensible for the tax deferral and the compounding, but it is a completely different decision from capturing the match, and people conflate the two constantly. One further ceiling can bite: total annual additions — your ordinary deferrals plus all employer money — cannot exceed the lesser of 100% of compensation or $72,000 for 2026. Catch-up contributions sit outside that cap, so only your regular deferrals eat into the employer’s room. If a very large deferral plus a generous match would breach $72,000, the match is what gets truncated. Growth follows the SEC’s compound-interest convention. The annual total is split into twelve equal deposits; each month the running balance grows by one-twelfth of your nominal annual return and the deposit lands at month end, so December’s deposit earns nothing that year. Salary is raised by your growth rate only after all twelve months are complete. The 2026 dollar limits are held fixed in nominal terms for every future year on purpose. The IRS has not issued limits for 2027 and beyond, and guessing at future cost-of-living adjustments would make a shared result URL quietly change meaning. In practice the limits usually rise, so a long projection where you are pinned at the cap tends to understate what you can actually contribute. Also note the model assumes the employer match is fully vested; if you leave before your plan’s vesting schedule completes, some of that money is forfeited. For the tax-treatment question this projection deliberately ignores — traditional deferral versus Roth — compare accounts with the IRA calculator, check Roth eligibility against the Roth IRA contribution limits, and see how the balance is eventually drawn down using the retirement calculator.