401(k) Calculator (United States)
The 401(k) is the most common retirement savings plan in the United States: you contribute part of your salary before taxes, your employer usually matches a percentage of what you put in, and the money grows invested for decades. This calculator projects the balance you could build up to your retirement age by combining three engines: your monthly contributions, the employer match and compound interest on everything invested. It is the clearest way to see why starting early and not leaving the match on the table radically change the final result.
Projected balance at retirement
Your contributions
Employer contributions
Compound growth
Rough projection: assumes constant contributions and return, monthly compounding, and deducts neither taxes nor inflation. The 2026 personal contribution limit (IRS 402(g)) is USD 24,500 (plus USD 8,000 catch-up from age 50). Real market returns vary year to year. This is not financial advice.
Publicidad
How it works
The projection starts from your current balance and adds, month by month, your contribution plus the employer match, compounding everything at the annual return you expect. The monthly employer contribution is computed as a percentage of yours: if you put in USD 500 and your employer matches 50%, it adds USD 250, so USD 750 enter the account each month. The future-value-with-periodic-contributions formula turns those monthly flows, over the years left until retirement, into a final balance. The result breaks into three colors: how much you put in, how much the employer put in and — usually the largest slice over long horizons — how much compound interest generated. The legal personal contribution limit in 2026 is USD 24,500 a year (with USD 8,000 extra "catch-up" from age 50), but the employer match sits outside that cap.
401(k) contribution limits in 2026
The IRS sets each year how much you can contribute. For 2026 the limit on your personal contribution (elective deferral, section 402(g)) rose to USD 24,500. On top of that come catch-up contributions for those aged 50 or over, and a global cap that includes what the employer adds. These are the 2026 figures:
| Item | 2026 limit | Who it applies to |
|---|---|---|
| Personal contribution (402g) | USD 24,500 | All participants |
| Catch-up 50+ | + USD 8,000 | Those turning 50 or older in the year |
| Super catch-up 60–63 | + USD 11,250 | Those turning 60 to 63 (SECURE 2.0) |
| Total cap (415c) | USD 72,000 | Your contribution + the employer's |
The employer match and the power of compound interest
The employer match is, literally, free money: if your company matches 50% of what you contribute up to a limit, every dollar you put in becomes 1.50 before it is even invested. Not capturing the full match is leaving salary on the table. But the most powerful engine over the long run is compound interest. An example: a 30-year-old with USD 10,000 already saved who contributes USD 500 a month, with a 50% match (USD 250) and a 7% annual return, reaches age 65 with around USD 1.47 million. Of that total, they contributed about USD 210,000 out of pocket and the employer another USD 105,000; the rest — over a million — is pure compound growth. That is why time matters so much: the same contributions started at 40 instead of 30 produce less than half.
Publicidad
Preguntas frecuentes
- What exactly is a 401(k)?
- It is an employer-sponsored retirement savings plan in the United States. You contribute a percentage of your salary, usually before taxes (traditional 401k) or after (Roth 401k), and that money is invested in funds until you retire. The big advantage is the tax deferral and, above all, the employer match, which is extra money many companies add to your account.
- What does the employer "match" mean?
- It is the contribution your company puts into your 401(k) matching part of yours. A typical match is "50% up to 6% of salary": it means that if you contribute 6% of your pay, the employer adds half of that. That is why it pays to contribute at least enough to capture the full match: below that point, you are giving up free money.
- How much can I contribute in 2026?
- The limit on your personal contribution in 2026 is USD 24,500. If you are 50 or older, you can add USD 8,000 of catch-up, and between 60 and 63 the extra rises to USD 11,250. The employer match does not count against that personal limit, though there is a global cap (415c) of USD 72,000 that adds your contribution plus the employer's.
- Why does compound interest weigh so much in the result?
- Because each year the returns are generated not only on what you contributed, but also on the gains of previous years. Over horizons of 30 or 40 years, that snowball means most of the final balance is not your contributions but the accumulated growth. It is also why starting ten years earlier can more than double the result with the same monthly contribution.
- Does the calculator deduct taxes and inflation?
- No. It shows the projected gross balance in nominal dollars, without subtracting the taxes you will pay on withdrawal (in a traditional 401k) or adjusting for inflation. It is useful for comparing contribution and return scenarios, but the real purchasing power of that balance decades from now will be lower. Take it as a rough estimate, not as financial advice.