This 401(k) calculator shows exactly how much your retirement account will grow based on your contributions, employer match, and investment returns. Updated with 2026 IRS contribution limits and catch-up provisions, this is the most accurate free 401(k) calculator available.

How to Use the 401(k) Calculator

Enter your current age and planned retirement age. The longer your runway, the more powerful compounding becomes. A 25-year-old who contributes $300/month has over 40 years for that money to grow — the same $300/month started at 45 has only 20 years, resulting in roughly 3× less final balance even with identical contributions.

Enter your current 401(k) balance, your annual salary, and your contribution percentage. The calculator automatically validates your contribution against the 2026 IRS limits: $23,500 for workers under 50, $31,000 for workers 50–59 and 64+, and $34,750 for workers aged 60–63 under the SECURE 2.0 “super catch-up” provision.

Enter your employer match. A common match is 100% up to 6% of salary — meaning if you earn $70,000 and contribute 6% ($4,200), your employer adds another $4,200. That’s an immediate 100% return on those dollars before any investment growth. If your employer offers a match, contributing at least enough to capture the full match is always the right financial move — it’s free money.

The expected annual return is your projected investment growth rate. A diversified index fund portfolio has historically returned 7–10% annually before inflation. The default 7% is a conservative estimate that accounts for fees and sequence-of-returns risk. The calculator shows both a nominal balance and an inflation-adjusted balance so you know what your savings will actually be worth in today’s dollars.

Understanding Your 401(k) Results

The results break down your final balance into three components: your own contributions, your employer match received, and investment growth. For most people, investment growth ends up being the largest component over a long career — sometimes larger than all contributions combined. This is the magic of compounding: returns generating returns, year after year.

The year-by-year chart makes compounding tangible. Notice that the balance grows slowly in the early years and then accelerates dramatically in the later years. This acceleration is why financial advisors are so insistent about starting early — the last 10 years before retirement typically account for more growth than the first 20 years combined, if you start young enough.

Frequently Asked Questions

What is the 2026 401(k) contribution limit?

For 2026, the IRS employee contribution limit is $23,500 for workers under age 50. Workers aged 50–59 and 64 and older can contribute up to $31,000 (including a $7,500 catch-up). Workers aged 60–63 benefit from the SECURE 2.0 “super catch-up” allowing contributions up to $34,750. Employer contributions do not count toward these employee limits.

Should I choose a traditional 401(k) or Roth 401(k)?

Traditional 401(k) contributions are pre-tax — you reduce your taxable income today, but pay taxes on withdrawals in retirement. Roth 401(k) contributions are after-tax — no deduction now, but qualified withdrawals in retirement are completely tax-free. If you expect to be in a higher tax bracket in retirement (common for young earners), Roth is usually better. If you’re in your peak earning years, traditional often makes sense. Many financial planners recommend splitting contributions for tax diversification.

What happens to my 401(k) if I change jobs?

You have four options: (1) leave it with your old employer’s plan, (2) roll it over to your new employer’s 401(k), (3) roll it over to an IRA, or (4) cash it out (which triggers income tax plus a 10% early withdrawal penalty if under age 59½ — almost always a bad idea). Rolling to an IRA generally gives you the most investment choices and lowest fees.

Is a 401(k) better than an IRA?

They’re complementary. A 401(k) has higher contribution limits ($23,500 vs $7,000 for an IRA in 2026) and may include employer matching. An IRA typically offers more investment choices and potentially lower fees. The conventional wisdom is: first contribute enough to your 401(k) to get the full employer match, then max out an IRA, then go back and max out the 401(k) if you have more to invest.

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