401(k) Retirement Calculator
Project your 401(k) balance at retirement, combining your own contributions, a flat employer match, and compound investment growth over time.
Calculator verified • Last updated: August 2026
Your 401(k) Details
Balance = P(1+r)ⁿ + (Cyou + Cemployer) · [(1+r)ⁿ − 1] / r
If you left before vesting: — is roughly what you'd have after — years if you left the company and forfeited 100% of the employer match (and its growth) up to that point, keeping only your own contributions and their growth. Real vesting/forfeiture rules vary by plan.
Year-by-Year Breakdown
| Year | Starting Balance | Your Contrib. | Employer Match | Growth | Ending Balance |
|---|
Growth Over Time
Your own contributions form the base, the employer match adds a second layer for free, and investment growth compounds on top of both — which is why the green band on top widens faster than the two below it the longer the money stays invested.
Simplified match: this calculator models your employer match as a flat percentage of salary, not a full tiered formula (e.g. "50% up to 6%") — but the Match Cap field above lets you cap how much of your contribution rate is eligible, so contributing past the cap won't grow your match further, the way many real capped plans work. Enter the flat rate that best approximates your real plan's match, and set the cap to your plan's eligible-contribution ceiling (or leave it at 100 for no cap).
2026 401(k) limit reference: the IRS caps your own elective-deferral contributions at roughly 24,500 dollars a year, or roughly 32,500 dollars combined if you're 50+ and use the catch-up allowance (ages 60-63 get a larger "super catch-up" instead). This calculator checks your entered contribution against that reference figure and shows a warning if it's exceeded — but always verify the exact current-year limit with your plan administrator or the IRS.
How This 401(k) Projection Works
A 401(k) grows from three sources: the balance you already have, the portion of your paycheck you elect to contribute, and — for many employer plans — a matching contribution added on top of yours. This calculator projects all three forward year by year, compounding your investment return on the running balance the same way a savings account compounds interest, except the contributions here come from two sources instead of one.
Why the Employer Match Is Modeled as a Flat Percentage (Plus an Optional Cap)
Real 401(k) match formulas are often tiered — a common example matches 50 cents on the dollar up to 6% of salary, meaning the employer effectively adds 3% of salary once you contribute at least 6% yourself, with no extra match for contributing beyond that. Modeling every possible tier structure would make this calculator far more complex without necessarily making it more accurate, since match formulas vary enormously between employers. Instead, this calculator asks for a flat employer-match percentage of salary plus an optional Match Cap — plug in your plan's effective match rate (3% in the example above), and if your plan only matches contributions up to a certain percentage (like the 6% cap in that example), set the Match Cap field to match; leave it at 100 for no cap, which reproduces the original uncapped, flat-percentage behavior exactly. Check your plan documents or HR department for your actual match structure if you're unsure.
The Compound Growth Formula
Every year, your existing balance grows by the expected return, and that year's combined contributions (yours plus your employer's) are added and begin compounding from that point forward.
A: the projected balance at retirement.
P: your current 401(k) balance.
r: the periodic (monthly) rate of return.
n: the total number of months until retirement.
Cyou: your own monthly contribution.
Cemployer: your employer's monthly match contribution.
The calculator actually computes this month by month rather than plugging directly into the closed-form formula above, so the year-by-year table and chart show an exact running balance at every step, split out by source.
Worked Example: 30-Year-Old, 25,000 Dollars Balance, Retiring at 65
Using the calculator's own default inputs — a 25,000-dollar starting balance, a 70,000-dollar salary, contributing 6% with a 3% flat employer match, growing at 7% annually until retirement at 65 — the projected balance reaches roughly 1,233,000 dollars after 35 years. Of that, 147,000 dollars came from your own contributions and about 73,500 dollars from the employer match; the remaining roughly 1,012,700 dollars — well over three-quarters of the final balance — is investment growth compounding on top of both, including growth on the original 25,000-dollar balance itself.
401(k) Contribution Limits
The IRS sets an annual dollar limit on how much you can personally contribute to a 401(k) through salary deferral — roughly 24,500 dollars for 2026 — with a higher "catch-up" limit available once you turn 50 (roughly 8,000 dollars more, or a larger "super catch-up" for ages 60-63 under SECURE 2.0). These limits adjust most years for inflation, so check your plan administrator or the current IRS guidance for this year's exact figures rather than assuming last year's numbers still apply. This calculator compares your first year's contribution amount against these reference figures and shows a warning if it's exceeded, but always verify the exact current-year limit yourself.
Common 401(k) Planning Mistakes
Not contributing enough to capture the full employer match is one of the most common — leaving match money on the table is turning down guaranteed, immediate return that no investment return alone can match; the calculator flags this directly with an inline note if your entered contribution rate falls short. Assuming salary (and therefore contributions) will stay flat for decades is another gap worth being aware of — most careers see at least some salary growth, which would grow both your own contributions and your match faster than the default flat-salary assumption shows (use the optional Annual Salary Growth field to model this). Forgetting that traditional 401(k) withdrawals are taxed as ordinary income in retirement is a third — the balance projected here is pre-tax, not the amount you'll actually get to spend.
401(k) Terms You Should Know
Employer Match — additional money your employer contributes to your 401(k), typically tied to how much you personally contribute, up to some limit.
Vesting — the schedule by which employer-matched funds become fully yours; leaving a job before you're fully vested can mean forfeiting some or all unvested match money.
Elective Deferral — the portion of your paycheck you choose to redirect into your 401(k) before it's paid out to you.
Rollover — moving a 401(k) balance into another qualified retirement account (such as an IRA) without triggering taxes or penalties, typically done when changing employers.
This calculator provides estimates for educational and planning purposes only, based on a simplified flat-match, flat-salary model. It is not financial or tax advice. Actual results depend on your plan's real match formula, salary changes, fees, and investment performance. Consult a qualified financial advisor for guidance specific to your situation.
Frequently Asked Questions
How does this calculator model my employer match?
As a flat percentage of your salary added every year, on top of your own contribution, with an optional Match Cap field so plans that only match contributions up to a set percentage of salary (a common real-world shape, e.g. matching 50% of the first 6% you contribute) can be modeled too — contributing past the cap won't grow the match further. Many real plans use a tiered formula instead; this calculator still simplifies that into one flat rate plus a cap rather than modeling every possible tier structure. Check your plan documents for your actual match formula and enter the equivalent flat rate and cap.
Does the projected balance account for taxes?
No. This projects your account balance before any withdrawal taxes. A traditional 401(k) grows tax-deferred, but withdrawals in retirement are taxed as ordinary income, so your actual spendable amount will be lower than the balance shown here.
Does salary growth or inflation affect this projection?
By default this calculator assumes your annual salary stays flat, for simplicity, but the optional Annual Salary Growth field lets you model a rising salary using your own assumed growth rate — both your contributions and your employer's match then grow with that rising salary each year. It is a user-provided assumption, not a prediction of your real future raises.
What rate of return should I use?
Many long-term 401(k) projections use 6-8% as a rough historical stock-market average, though your actual mix of stocks, bonds, and funds will determine your real return. Past performance never guarantees future results.
Am I contributing enough to get my full employer match?
The calculator checks your entered contribution percentage against the Match Cap field and shows an inline note estimating how much employer match you're leaving unclaimed each year if your contribution rate is below the threshold needed to capture the full modeled match.
If I switch jobs before I'm fully vested, do I lose any of the employer match shown here?
Possibly, depending on your plan's vesting schedule. The optional Years Until Fully Vested field lets you see an illustrative "if you left before vesting" balance, assuming you forfeited 100% of the employer match (and its growth) up to that point. Real vesting schedules vary by plan — check your plan documents for the actual forfeiture rules.