Free 401(k) calculator
Project your 401(k) balance at retirement from salary, contribution, employer match, return, and years — updated live, as you type.
On this page12 sections
Estimates only, based on a constant real return and steady saving. Not financial advice.
Results are estimates. Consult a professional.
What the 401(k) calculator projects
A 401(k) calculator projects what your workplace retirement account will be worth at the age you stop working, by compounding three streams of money together: the savings you already hold, the contributions you add every month, and the employer match your plan pays on top. Enter your age, retirement age, current balance, monthly contribution, expected return, and your employer's match terms, and it returns the projected nest egg the moment you type — alongside the inflation-adjusted value in today's dollars.
A 401(k) is an employer-sponsored, tax-advantaged plan: with a traditional 401(k) your contributions come out of pay before income tax and the balance grows tax-deferred until you withdraw it; the money compounds without the annual drag of taxes on dividends or gains. This tool is built to answer the single most useful planning question — am I contributing enough, early enough, to land where I want to be? — not to file your taxes.
How 401(k) growth is calculated
The calculator steps the balance forward one month at a time. Each month it grows the current balance by one-twelfth of the annual return, then adds your monthly contribution and your employer's monthly match. Doing it monthly — rather than once a year — matches how payroll and most plans actually work.
Two figures drive the outcome more than any other: time and the match. Time, because each early dollar compounds for decades; the match, because it is an immediate, guaranteed return on your contribution before the market does anything. A 100% match is a 100% instant gain on every matched dollar — which is why financial planners treat contributing at least up to the full match as the first rule of 401(k) saving.
IRS — 401(k) limit increases to $23,500 for 2025; catch-up $7,500, and $11,250 for ages 60–63 (SECURE 2.0).How to use the 401(k) calculator inputs
- Current age and retirement age. The gap between them is your compounding runway — the single biggest lever in the whole projection.
- Current savings. Your 401(k) balance today. It compounds from day one, so even a modest starting balance grows substantially over a long horizon.
- Monthly contribution. What you put in each month from pay. Stay inside the 2025 elective limit of $23,500 (about $1,958/month) — more if you qualify for catch-up.
- Expected return. A long-run average. 6–7% is a common planning figure for a diversified stock-and-bond portfolio after a 2–3% inflation assumption; the tool also shows the inflation-adjusted value separately.
- Employer match % and match cap. Read these straight off your plan summary — for example '100% up to 6% of salary'. Enter 100 and 6.
- Annual salary. Used only to size the match cap, since the cap is a percentage of pay.
A worked 401(k) example with employer match
Maria is 35, plans to retire at 65, and already holds $50,000 in her 401(k). She contributes $500 a month, expects a 7% annual return, earns $80,000, and her employer matches 100% of contributions up to 6% of salary. Here is exactly how the calculator builds her result.
Step 1 — Size the employer match
Maria contributes $6,000 a year ($500 × 12). The match cap is 6% of her $80,000 salary, or $4,800 — less than her $6,000, so only $4,800 is matchable. At a 100% match that adds $4,800 a year ($400/month) of free employer money on top of her own contributions.
Step 2 — Compound month by month
Step 3 — Read the result
The lesson in the numbers: of the $1.5M, only $324,000 was money paid in — the other ~$1.18M is growth. The employer's $144,000 match compounds into about $488,000 of the final balance, the $50,000 starting balance grows to roughly $406,000, and the rest comes from Maria's own contributions. Capturing the full match is the highest-return move on this page.
2025 401(k) contribution limits
The IRS caps how much you may defer each year. For 2025, the employee elective deferral limit rose to $23,500. Workers 50 and older may add a catch-up; under SECURE 2.0 a new, larger super-catch-up applies specifically to ages 60–63.
| 2025 limit | Amount | Total you can defer |
|---|---|---|
| Elective deferral (under 50) | $23,500 | $23,500 |
| Age 50–59 catch-up | +$7,500 | $31,000 |
| Age 60–63 super catch-up | +$11,250 | $34,750 |
| Age 64+ catch-up | +$7,500 | $31,000 |
2025 employee deferral limits. The super catch-up applies only in the years you are 60, 61, 62, or 63. Employer match does not count toward the elective limit. Source: IRS, 2025 limits.
Who benefits most from running the numbers
- Early-career savers — the projection shows how much a 25-year head start adds, making a modest contribution today feel worth the trade-off.
- Anyone leaving match on the table — set your real contribution, then raise it to the match cap and watch the gap. Declining a full match is leaving guaranteed money behind.
- Workers nearing 60 — model the $11,250 super catch-up across ages 60–63 to see how much it can add in the final stretch.
- Job changers weighing a new plan — compare a richer match at one employer against a higher salary at another by entering each plan's terms.
Once you know your projected balance, weigh the tax election with the Roth 401(k) vs traditional 401(k) calculator, and see what touching the money early would cost with the 401(k) early withdrawal penalty calculator.
Common 401(k) mistakes and gotchas
- Contributing below the match. The most expensive mistake — every unmatched percentage point is a forfeited raise. Hit the cap first.
- Forgetting vesting. The calculator counts the full match, but if you leave before you are vested you may keep only part of it. Check your plan's vesting schedule.
- Front-loading and missing match. If you hit the $23,500 limit early in the year, some plans stop matching for the remaining months. A 'true-up' provision fixes this — confirm yours has one.
- Treating the projection as a guarantee. The model uses one constant return; real markets swing. Re-run it when your contribution, salary, or outlook changes.
- Ignoring fees. Fund expense ratios quietly reduce your real return. A 1% annual fee can erase a large slice of a multi-decade balance.
Accuracy, assumptions, and sources
This 401(k) calculator compounds your balance monthly at a constant expected return, adds your contributions and the employer match (capped by your contribution and the salary cap), and discounts the result by 3% a year to show the inflation-adjusted value. It assumes a fixed return, a steady contribution, and full vesting of the match. Real returns vary, salaries and contributions change, and plan rules differ — so the output is a planning estimate, not financial advice. Verify your own contribution room and plan terms before acting.
IRS — 401(k) plans: deferral limits, employer contributions, and how 401(k) accounts work.IRS — Retirement topics: 401(k) and profit-sharing plan contribution limits.Frequently asked questions about the free 401(k) calculator
About this 401(k) calculator
This 401(k) calculator projects your workplace retirement balance by compounding your current savings, monthly contributions, and employer match month by month at your expected return, then shows the result in both nominal and inflation-adjusted dollars. It is built for the planning question that matters most — whether you are contributing enough, early enough, and at least up to your full employer match.
It uses current 2025 IRS contribution limits and sits alongside the rest of our retirement calculators; browse the full library on the calculators home. Figures are planning estimates, not financial advice.