401(k) Calculator: What Yours Grows To

What your 401(k) projection shows

The balance is split three ways deliberately, because the three parts behave differently. Your contributions are money you chose not to spend. The employer match is compensation you only receive if you claim it. And investment growth is what time does to both — on a long horizon it usually ends up the largest of the three.

The line to act on is employer match you leave behind. It appears whenever your contribution percentage sits below the level your employer will match, and it is money forgone every year, not once. There is no investment decision on this page that comes close to it for certainty of return.

If your percentage would exceed the annual IRS deferral limit, the projection quietly uses the limit instead and says so — a forecast built on a contribution the law does not permit is worse than no forecast.

How to use this 401(k) calculator

Age and retirement age — the gap is the compounding runway, and it matters more than the return you assume.
Salary and current balance — gross pay, and what the account holds today.
Your contribution as a percentage of salary. Percentages, not dollars, because that is how payroll works and how the contribution grows with your pay.
The match formula in two parts: how many cents per dollar your employer adds, and the percentage of salary they will do it up to. "50% up to 6%" is the most common arrangement in the US — read your plan summary rather than guessing.
Expected return and salary growth — assumptions. Run the projection twice, pessimistically and optimistically, and treat the gap as the honest answer.

The employer match is the whole game early on

A match of fifty cents on the dollar is an immediate 50% return on the money you contribute, before the market does anything at all. Nothing else available to an ordinary investor competes with that, which is why the standard advice is to contribute at least up to the match before considering any other account — including a Roth IRA, and usually before extra payments on low-rate debt.

Two details decide whether you actually keep it. The formula: "50% up to 6%" means contributing 6% of salary earns you 3% of salary from your employer, and contributing 3% earns only 1.5% — you cannot make up the difference later. Vesting: many plans require you to stay a certain number of years before the match is fully yours. Your own contributions are always yours; the match may not be until you vest, which is worth knowing before you resign.

A true-up provision matters too if your contributions are uneven across the year. Without one, front-loading your contributions and hitting the annual limit in September can cost you the match for the remaining months.

How much you can contribute in 2026

The IRS caps what you may defer from your own pay at $24,500 for 2026. From age 50 you may add a catch-up of $8,000, taking the total to $32,500. For the four years you are 60, 61, 62 and 63, SECURE 2.0 raises that catch-up to $11,250 — a total of $35,750 — after which it reverts to the ordinary age-50 amount.

Two things that limit does not include. Employer matching contributions sit outside it, under a much higher combined ceiling, so a match never eats into your own allowance. And the limit is per person across all 401(k)-type plans, not per employer — if you change jobs mid-year, both plans count toward the same total, which is a common and expensive oversight.

Figures from IR-2025-111. They are indexed annually, so a projection decades out understates what you will actually be allowed to contribute.

Traditional or Roth 401(k)?

Most plans now offer both. A traditional deferral reduces your taxable income now and is taxed on the way out; a Roth deferral gives no deduction now and is never taxed again. The deferral limit is shared between them — you choose the split, not a bigger total.

The decision reduces to whether your tax rate in retirement will be higher or lower than today. Nobody knows, which is a strong argument for holding some of each and keeping the choice open. Two asymmetries are worth noting: a Roth 401(k) has no lifetime required minimum distributions for the owner, while a traditional one does; and the employer match is generally deposited as traditional money even if your own contributions are Roth, so most savers end up with both regardless.

Fees and what they cost you

Plan fees are the quiet variable this calculator does not model, because they vary by plan and are not something we can source for yours. They matter more than most people assume: on a long horizon, a difference of one percentage point in annual costs can reduce a final balance by a fifth or more, because the fee compounds against you exactly as returns compound for you.

Your plan is required to disclose them. Look for the expense ratio of each fund plus any administrative charge, and prefer low-cost index options where the menu offers them. If you want to see the effect, run this projection twice with the return reduced by your all-in fee — the difference is what the plan costs you.

An old plan from a former employer is worth the same attention. Rolling it into an IRA usually widens the investment choice and can cut costs, though it also gives up the stronger creditor protection some plans carry.

What the match cliff costs — a worked example

Take someone earning $60,000 whose employer matches dollar for dollar up to 6% of salary. Contributing 6% puts in $3,600 and collects $3,600 — the employer doubles the money before a single investment decision is made. Contributing 3% puts in $1,800 and collects $1,800, so the shortfall is not the $1,800 they did not contribute; it is the $1,800 of employer money they also declined.

Over thirty-five years at a 7% return, that forgone half of the match alone compounds into a figure in the hundreds of thousands — and the calculator prints it for your own numbers rather than leaving you to work it out. Raising a contribution from 3% to 6% costs $150 a month of take-home pay at that salary, less after the tax deduction on a traditional deferral, and the paycheck calculator shows what the change actually does to a pay stub.

The general rule follows: contribute to the match threshold before anything else, because it is the only guaranteed return in personal finance. Only after that does the ordinary hierarchy apply — high-rate debt, then tax-advantaged saving, then everything else.

Taking money out early

A 401(k) is deliberately hard to reach before 59½. A withdrawal before then is normally taxed as ordinary income and carries a 10% penalty on top, so a $20,000 withdrawal can net barely $13,000 — and the balance stops compounding permanently, which usually costs more than the tax did.

There are narrower routes. A plan loan, where offered, lets you borrow up to a limit and repay yourself with interest; leave the job and the outstanding balance typically becomes due, or is treated as a distribution. Hardship withdrawals exist for specific defined needs. And the rule of 55 lets someone who leaves an employer in or after the year they turn 55 take distributions from that employer’s plan without the 10% penalty — an exception that does not apply to IRAs, which is a reason not to roll a plan over hastily at that age.

What this calculator assumes

A steady return, every year. Markets deliver an average as a sequence, and the order of good and bad years matters enormously in the decade around retirement.
Contributions and match at year end, which is slightly conservative — real payroll contributions arrive through the year and earn a little more.
Today’s IRS limits, held flat. They are indexed, so real future limits will be higher.
No fees. See above; subtract your all-in cost from the return to model them.
No loans, hardship withdrawals or job changes interrupting the contributions.
Full vesting. If you leave before vesting, some or all of the match is forfeited.

These are planning estimates, not advice, and not a projection of any specific plan’s performance.

401(k) questions people ask

How much should I contribute to my 401(k)?

At minimum, enough to capture the full employer match — below that you are declining part of your pay. Beyond that, a common target is 15% of gross salary including the match, but the right figure depends on when you want to retire and what else you are saving for.

Does the employer match count toward my contribution limit?

No. The elective deferral limit applies only to money from your own pay. Employer contributions fall under a separate, much higher combined ceiling, so a generous match never reduces what you are allowed to put in yourself.

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

You can usually leave it in the old plan, roll it into the new employer’s plan, or roll it into an IRA. Cashing it out is the expensive option: income tax plus, in most cases, a 10% early-withdrawal penalty, and the balance stops compounding permanently.

Can I contribute to both a 401(k) and an IRA?

Yes — the limits are separate. Being covered by a workplace plan can restrict whether your traditional IRA contribution is deductible at higher incomes, and Roth IRA eligibility phases out on income regardless, but the 401(k) itself does not stop you contributing.

What return should I assume?

Something defensible rather than flattering. Long-run US stock returns have averaged in the region of 7% a year after inflation over very long periods, but any individual decade can fall well short. Model lower and treat anything better as upside.