What the 401(k) Calculator does
A 401(k) is the workplace retirement account most US employees save through: you defer a slice of every paycheck into it, your employer often adds a matching contribution, and the whole balance grows tax-deferred until you withdraw it in retirement. This calculator projects what that balance could be worth on the day you retire, then splits it into the four pieces that built it: your starting balance, everything you contributed, everything your employer matched, and the investment growth compounded on top.
It models the parts that make a real 401(k) projection accurate rather than a back-of-envelope guess: a tiered employer match (dollar-for-dollar up to one percentage of pay, then a lower rate up to a higher one), the $24,500 2026 IRS elective-deferral cap plus the $8,000 age-50+ catch-up, annual salary growth, and a year-by-year schedule you can read row by row. If you want the tax-free Roth version instead, use the Roth IRA calculator; for a broader "am I on track to retire" view, the retirement calculator brings in other income sources.
How the projection works
The engine runs one step per year from your current age to your retirement age. For each year t it does four things in order:
- Grows your salary: this year’s salary is last year’s multiplied by (1 + your salary-increase rate).
- Takes your contribution: your contribution percentage of that salary, capped at the IRS elective-deferral limit (plus the catch-up once you turn 50, if enabled).
- Adds the employer match: computed on your deferral percentage through the two match tiers you entered.
- Compounds the balance: the prior year-end balance grows at your expected return, then this year’s contribution and match are added on top.
balancet = balancet-1 × (1 + r) + employeeContributiont + employerMatcht
employerMatch = rate1 × min(d, ceiling1) × salary + rate2 × max(0, min(d, ceiling2) − ceiling1) × salary
Here r is your annual return and d is your deferral as a fraction of salary. Contributions are treated as end-of-year (an ordinary annuity), the standard convention for long-horizon retirement projections.
The 2026 IRS contribution limits
The IRS caps how much you can defer from your own salary each year (the 402(g) limit) and raises that cap for older workers. The calculator applies these 2026 figures automatically, so a high contribution percentage on a large salary won’t overstate your savings:
| 2026 limit | Amount |
|---|---|
| Employee elective deferral (402(g)) | $24,500 |
| Age 50+ catch-up (standard) | $8,000 |
| Age 50+ total (base + catch-up) | $32,500 |
| Age 60–63 catch-up (SECURE 2.0) | $11,250 |
| Overall additions cap (415(c), excl. catch-up) | $72,000 |
The calculator applies the standard 50+ catch-up but not the higher age-60–63 SECURE 2.0 amount, and it does not enforce the overall 415(c) cap on your combined employee-plus-employer total — both are documented limitations below.
Worked example: a full 37-year career
Suppose you’re 30 with $25,000 already saved, earning $75,000 a year (rising 2% annually), deferring 10% of pay into a plan that matches 100% up to 3% then 50% up to 5%, and you expect a 7% return through age 67. These are the calculator’s defaults, and the same engine produces the numbers below:
| Component | Amount |
|---|---|
| Starting balance | $25,000 |
| Your contributions (37 years) | $405,257 |
| Employer match (37 years) | $162,103 |
| Investment growth | $1,843,247 |
| Projected balance at 67 | $2,435,606 |
The striking part is how small your own contributions look next to the total: decades of compounding turn a modest, steady deferral into the majority of the final balance. That is the entire case for starting early — every year you delay is a year the growth column doesn’t get. To see the same effect on a pure lump sum, try the compound interest calculator.
Pre-tax 401(k) vs Roth: which balance is this?
The projected balance here is pre-tax. A traditional 401(k) is funded with before-tax dollars, so both your contributions and all the growth are taxed as ordinary income when you withdraw them in retirement. That is the opposite of a Roth account, where you pay tax now and withdrawals are tax-free later. The table shows how the two differ at a glance:
| Feature | Traditional 401(k) | Roth |
|---|---|---|
| Contributions | Pre-tax (lower taxable income now) | After-tax (no deduction now) |
| Withdrawals in retirement | Taxed as ordinary income | Tax-free if qualified |
| Employer match | Common | Match goes to a pre-tax account |
| This projection is | A pre-tax figure | See the Roth IRA calculator |
Because the two are taxed at opposite ends, comparing them well means estimating your tax rate today versus in retirement — a decision the retirement planning calculator and the investment calculator can help you frame.
Withdrawal rules: early withdrawals and required distributions
Growing the balance is only half the story — when and how you can take money out matters just as much. Two IRS rules bookend a traditional 401(k): a penalty for taking money out too early, and a requirement to eventually take money out once you’re older.
- Early withdrawal penalty. Distributions taken before age 59½ generally owe a 10% additional tax on top of ordinary income tax, unless an exception applies — common ones include separating from your employer at age 55 or later (the “Rule of 55”), total and permanent disability, a qualified birth or adoption (up to $5,000), certain unreimbursed medical expenses above 7.5% of adjusted gross income, or a series of substantially equal periodic payments.
- Required minimum distributions (RMDs). Under SECURE 2.0, most participants must start withdrawing from a traditional 401(k) at age 73. If you’re still working for the plan’s sponsor past 73 and aren’t a 5%-or-greater owner of the business, many plans let you delay RMDs until you actually retire — check your plan document. Missing an RMD carries an excise tax of 25% of the shortfall (reduced to 10% if corrected within two years).
This calculator projects the balance you’ll accumulate by retirement age — it does not model withdrawals, penalties, or RMDs after that point. For the decumulation side, the retirement calculator estimates how long a balance can sustain withdrawals.
Assumptions and limitations
A projection is only as good as its assumptions. This calculator deliberately keeps the model simple and transparent, which means it leaves some real-world complications out:
- Constant return and salary growth. Real markets are volatile and can post negative years; real careers include raises, job changes and gaps. Treat the figure as an illustration of a steady trajectory, not a guarantee.
- No vesting schedule. The match is assumed fully vested. If you leave before a cliff or graded schedule completes, you may forfeit unvested employer money.
- Only the 402(g) cap is enforced. The overall 415(c) annual-additions limit ($72,000 in 2026) on your combined employee + employer total is not checked, and the higher age-60–63 SECURE 2.0 catch-up is not modelled.
- Nominal, pre-tax dollars. Figures are not inflation-adjusted (interpret your return as a real rate if you want today’s dollars), and taxes on withdrawal are not deducted.
- Limits change every year. The 2026 IRS constants are re-verified from IRS primary sources; re-check them each tax year.
Frequently asked questions
How does this 401(k) calculator project my retirement balance?+
It runs a year-by-year simulation from your current age to your retirement age. Each year your salary grows by your expected annual increase, your employee contribution is your chosen percentage of that year's salary (capped at the IRS elective-deferral limit), your employer adds a match based on your deferral percentage and the tiered match rates you enter, and the prior year-end balance plus that year's contributions grow at your expected annual return. The balances, contributions and match are summed across every year to produce your projected balance at retirement.
What is the 2026 401(k) employee contribution limit?+
For 2026, the IRS elective-deferral limit for 401(k), 403(b), governmental 457 and Thrift Savings Plan accounts is $24,500. This calculator automatically caps your annual employee contribution at this limit (plus the catch-up amount if you're 50 or older and have the catch-up toggle on), even if your entered contribution percentage would imply a larger dollar amount.
What is the 401(k) catch-up contribution for people 50 and older?+
Employees who are age 50 or older by the end of the year can contribute an additional $8,000 in 2026, on top of the standard $24,500 elective-deferral limit — for a total of up to $32,500. This calculator applies the catch-up automatically once your age at the start of a projection year reaches 50, if the 'include catch-up' option is enabled. Note that SECURE 2.0 provides an even higher catch-up ($11,250 in 2026) specifically for participants aged 60 to 63, which this calculator does not separately model — it always uses the standard 50+ catch-up amount.
How does the tiered employer match work in this calculator?+
Many employers match contributions in tiers — for example, 100% of the first 3% of salary you defer, then 50% of the next 2% (up to 5% total). Enter your tier 1 match rate and ceiling, and optionally a tier 2 match rate and ceiling. If your employer offers a single-tier match (e.g. '50% up to 6% of salary'), set the tier 2 rate to 0% and put your ceiling in tier 1. The employer match is calculated on your contribution percentage, not on your capped dollar contribution.
Is my employer match calculated before or after my contribution is capped by the IRS limit?+
This calculator computes your employer match based on your entered contribution percentage of salary, before applying the IRS 402(g) dollar cap to your own contribution. This mirrors how most real-world payroll systems calculate matching — the match formula looks at what percentage you’re deferring, not the dollar amount after any cap is applied. In practice, IRS limits rarely bind the match calculation because the combined match ceilings (typically well under 10% of salary) are far below the dollar-cap threshold for most salaries.
Is my projected 401(k) balance shown before or after tax?+
The projected balance is a pre-tax figure. A traditional 401(k) is funded with pre-tax dollars, and both your contributions and all investment growth are taxed as ordinary income when you withdraw them in retirement. This is different from a Roth IRA or Roth 401(k), where qualified withdrawals are tax-free. If you want to compare an after-tax retirement account, see our Roth IRA calculator.
Does this calculator account for 401(k) vesting schedules?+
No. This calculator assumes your employer match is fully vested and included in your balance throughout the projection. In reality, many employer matching contributions vest over a schedule (for example, 20% per year over five years, or a three-year cliff) — if you leave your job before you're fully vested, you may forfeit some or all of the unvested employer contributions. Check your plan document for your specific vesting schedule.
Does the calculator enforce the overall IRS annual-additions limit (Section 415(c))?+
No. The IRS also caps the combined total of your contributions, your employer’s match, and any other plan contributions at the lesser of 100% of your compensation or $72,000 in 2026 ($80,000 including the standard catch-up). This calculator enforces only the employee elective-deferral cap (402(g)); it does not check whether your combined employee-plus-employer total would exceed the 415(c) limit. For most salary and match combinations this limit is not binding, but very high earners with generous employer contributions should be aware of it.
What return rate should I use for my 401(k) projection?+
There's no single right answer — it depends on your investment mix. A diversified portfolio of stock index funds has historically returned around 7% annually after adjusting for inflation over long periods, which is why 7% is the calculator's default. A more conservative, bond-heavy portfolio might use 4-5%; an aggressive, stock-heavy portfolio held for decades might use 8-10%. Try a few different rates to see how sensitive your projected balance is to the assumption.
How much should I contribute to my 401(k) to get the full employer match?+
Contribute at least enough to reach the top of your employer's highest match tier — for example, if your plan matches 100% up to 3% then 50% up to 5%, contributing 5% of your salary captures the maximum available match (4% of your salary from your employer). Contributing less than that ceiling leaves free money on the table; contributing more is still valuable for your own retirement savings, but any dollars beyond the match ceiling don't earn additional employer money.
Can I use this calculator if I don't get an employer match?+
Yes. Set both the tier 1 and tier 2 employer match rates to 0%, and the calculator will project your 401(k) balance from your own contributions and investment growth alone, with no employer match added.
How accurate is this 401(k) projection?+
The math itself is exact for the inputs given, but the model relies on several simplifying assumptions: a constant annual return, a constant salary growth rate, a steady contribution percentage every year, and full vesting with no missed contributions, loans or withdrawals. Real careers include raises, job changes, market volatility, and life events that a static projection can't capture. Treat the result as an illustrative estimate of your trajectory under steady assumptions, not a guaranteed outcome — and revisit the calculator periodically with updated figures.
What happens if I withdraw from my 401(k) before age 59½?+
A distribution taken before age 59½ generally owes a 10% additional tax on top of ordinary income tax, unless an IRS exception applies — for example, separating from your employer at age 55 or later (the "Rule of 55"), total and permanent disability, a qualified birth or adoption (up to $5,000), certain unreimbursed medical expenses above 7.5% of your adjusted gross income, or a series of substantially equal periodic payments. This calculator projects your balance at retirement age; it does not model early-withdrawal penalties or taxes.
At what age do I have to start taking money out of my 401(k)?+
Under SECURE 2.0, most traditional 401(k) participants must begin required minimum distributions (RMDs) at age 73. If you're still working for the plan sponsor past 73 and own less than 5% of the business, many plans let you delay RMDs until you actually retire — check your plan document for this "still working" exception. Missing an RMD carries an IRS excise tax of 25% of the amount not withdrawn (reduced to 10% if you correct it within two years). This calculator projects accumulation up to retirement age and does not model RMDs.
Disclaimer
Sources
- IRS Newsroom — 401(k) limit increases to $24,500 for 2026 (elective deferral, 50+ catch-up, age 60-63 catch-up)
- IRS — Retirement Topics: 401(k) and Profit-Sharing Plan Contribution Limits (2026 elective-deferral and 415(c) annual-additions limits)
- IRS — Matching Contributions Help You Save More for Retirement (worked employer-match example)
- Wikipedia — 401(k) (plan mechanics, elective-deferral limit, 415 limit, catch-up eligibility)
- IRS Topic no. 558 — Additional tax on early distributions from retirement plans (10% penalty and exceptions)
- IRS — Retirement Topics: Required Minimum Distributions (RMDs) (age 73 start, excise tax on shortfall)
Formula and data last reviewed by the TheCalculatorHive team on 8 July 2026. Figures are for general information, not professional advice.
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