401(k) Calculator
Project your 401(k) balance at retirement with employer match.
401(k) at retirement
$802,814.72
$525.00/mo contributions
Total contributed
$209,000.00
Investment growth
$593,814.72
Employer match/yr
$2,100.00
Your 401(k) grows to $802,814.72 over 30 years. $593,814.72 of that is compound growth on top of $209,000.00 contributed.
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How the 401(k) Calculator works
The 401(k) Calculator projects your retirement account balance at a chosen retirement age by combining your own contributions, your employer's matching funds, and the power of compound growth over time. It's designed for U.S. employees who want a clear, data-driven picture of whether their current savings rate puts them on track for a comfortable retirement.
At its core, this calculator models how your 401(k) balance grows year by year using three engines: your pre-tax (or Roth) contributions, your employer match, and investment returns compounded over time. Each year, the tool adds your annual contribution plus any employer match to your existing balance, then applies your expected annual rate of return to the entire sum. This compounding effect — earning returns on both your principal and your accumulated gains — is what makes starting early so disproportionately powerful. Even a modest contribution in your 20s can be worth several times more than the same dollar contributed in your 40s.
Employer match is one of the most impactful variables in the model and is often misunderstood. Most U.S. employers offer a partial match — a common structure is 50% of contributions up to 6% of salary, meaning if you earn $80,000 and contribute 6% ($4,800), your employer adds $2,400. The calculator applies this match formula on top of your own contributions, effectively giving you an immediate 50% return on that portion of your savings before any market gains. Failing to contribute at least enough to capture the full employer match is widely regarded as the single biggest 401(k) mistake, since it is essentially leaving part of your compensation on the table.
The assumed annual rate of return is another critical lever. Historically, a diversified stock portfolio has returned roughly 7–10% per year before inflation, and 5–7% in real (inflation-adjusted) terms. The calculator typically uses a nominal rate — often defaulting to around 7% — to project your ending balance in future dollars. It's worth running scenarios with both conservative (5%) and optimistic (9%) rates to understand the range of possible outcomes, since even a 1–2 percentage point difference in annual returns compounded over 30+ years can shift your final balance by hundreds of thousands of dollars.
A common mistake users make is ignoring contribution limit changes and salary growth. The IRS adjusts 401(k) contribution limits annually (the 2024 limit is $23,000, with a $7,500 catch-up allowed for those 50+), and most people see their salary — and therefore their contribution amount — rise over time. A more accurate projection should account for annual salary increases, which in turn increase the dollar value of your contributions and employer match each year. Additionally, if you are close to or above the annual limit, the calculator can help you identify when you might hit that ceiling and need to redirect excess savings to an IRA or taxable brokerage account.
Formula
FV = Balance·(1+i)^N + Monthly·[((1+i)^N − 1)/i]
Pro tips
- Always contribute at least enough to capture your full employer match before directing any savings elsewhere — it is the highest guaranteed return available to you, often equating to 50–100% instant gains on those dollars.
- Increase your contribution rate by 1% each year, ideally timed to coincide with a salary raise, so you accelerate your balance without feeling a meaningful cut in take-home pay.
- Run the calculator with a conservative 5–6% return assumption alongside an optimistic 8–9% one; the gap in outcomes will reveal exactly how much risk your retirement timeline can — or cannot — afford.
- If you are 50 or older, input the full catch-up contribution amount ($7,500 in 2024) to see how aggressively using that IRS provision can close the gap if you started saving late.
- Factor in your target retirement spending, not just your balance — a common rule of thumb is the 4% withdrawal rule, meaning you need a balance roughly 25 times your expected annual retirement expenses to sustain withdrawals indefinitely.
Key terms
- 401(k) Contribution Limit
- — The maximum amount the IRS allows you to contribute to your 401(k) in a given tax year — $23,000 for 2024, plus a $7,500 catch-up contribution if you are age 50 or older.
- Employer Match
- — The additional amount your employer contributes to your 401(k) based on a formula tied to your own contribution, effectively a guaranteed return on that portion of your savings before any market growth.
- Compound Interest
- — The process by which your investment returns earn their own returns over time, causing your 401(k) balance to grow exponentially rather than linearly the longer it remains invested.
- Vesting Schedule
- — The timeline over which you earn full legal ownership of your employer's matching contributions — immediate, cliff, or graded vesting — which affects the real value of your match if you change jobs.
- Pre-Tax vs. Roth 401(k)
- — Pre-tax contributions reduce your taxable income now and are taxed at withdrawal; Roth contributions are made after-tax, but qualified withdrawals in retirement are completely tax-free.
- Real Rate of Return
- — Your investment return after subtracting inflation, which gives a more honest picture of the actual purchasing power your retirement savings will deliver.
