Short answer: A 30-year-old earning $70,000 who saves 10% with a 50% match on the first 6%, gets 3% raises and earns 7% a year could have about $2.06 million at 65, roughly $868,000 in today's dollars at 2.5% inflation. For 2026 you can contribute up to $24,500, plus catch-ups from age 50.
2026 401(k) limits
| Limit | 2026 |
|---|
| Employee contributions | $24,500 |
| Catch-up, age 50 and over | +$8,000 |
| Higher catch-up, ages 60–63 | +$11,250 (instead of $8,000) |
| Total employee + employer (excluding catch-ups) | $72,000 |
| Catch-ups must be Roth if prior-year wages exceed | $150,000 |
Source: IRS Notice 2025-67, as summarized by Ascensus. The calculator applies 2026 limits every year; real limits usually rise with inflation, so long projections near the cap are conservative.
The two decisions that matter most
Take the full match. Using the same example, contributing only 3% leaves half the match on the table and ends near $852,000. Contributing the 6% needed for the full match ends near $1.49 million: about $639,000 more, from an extra 3% of pay.
Start early. The same 10% plan started at 40 instead of 30 ends around $891,000 instead of $2.06 million. Those first ten years of contributions have the longest time to compound, so they end up doing a lot of the work.
Roth or traditional doesn't change these numbers, only when you pay the tax. If you're not sure your savings are on track, check your other savings with the savings interest calculator, and see how compound growth works in the rule of 72.
Frequently asked questions
What is the 401(k) contribution limit for 2026?
$24,500 in employee contributions. Workers 50 and older can add an $8,000 catch-up, and those aged 60 to 63 get a higher $11,250 catch-up instead. Total contributions from you and your employer are capped at $72,000, not counting catch-ups.
How much should I contribute to my 401(k)?
At minimum, enough to get your full employer match, because that's an instant return you can't get anywhere else. In the example here, raising contributions from 3% to the 6% needed for the full match adds about $639,000 by age 65.
Is a Roth 401(k) better than a traditional 401(k)?
The growth math is the same; the difference is tax timing. Traditional contributions cut your taxes now and withdrawals are taxed later; Roth contributions are taxed now and qualified withdrawals are tax-free. Roth tends to suit people who expect a higher tax rate in retirement. From 2026, catch-up contributions for people whose prior-year wages exceeded $150,000 must go in as Roth.
What return should I assume?
Many planners use 5–7% a year for a stock-heavy portfolio over long periods, before inflation, but returns aren't guaranteed and vary year to year. Try a lower number too, so a weak decade doesn't surprise you. The calculator also shows the result in today's dollars.
Does the calculator include taxes and fees?
No. It projects the account balance before income tax on withdrawals and assumes fund fees are reflected in the return you enter. A fund charging 1% a year instead of 0.1% can cost a large share of the final balance over decades, so check your plan's expense ratios.
Disclaimer: Projections for education only, not investment, tax or retirement advice. Returns are not guaranteed. Assumes contributions spread evenly through the year and a constant return.