401(k) Calculator

The short answer

• In 2026 you can put up to $24,500 of your pay into a 401(k), plus $8,000 from age 50 or $11,250 from 60 to 63.
• Always contribute at least enough to get your employer’s full match. It is the best return you will find.
• A 30-year-old earning $75,000 who saves 6% with a 50% match, starting from $20,000, could reach about $1,644,822 by 67 at 7% a year before 0.5% fees. That is about $659,684in today’s dollars.
• Fees, time in the market and your contribution rate change the result far more than most people expect.

What a 401(k) is

A 401(k) is a retirement savings plan run by an employer. You choose a share of each paycheck to put in, and it goes into investments you pick from the plan’s menu, usually mutual funds or target-date funds. Many employers add money of their own, either as a match on what you put in or as a flat contribution.

The account has tax advantages. With traditional contributions, the money comes out of your pay before federal income tax, so your taxable income falls; you pay tax when you withdraw it in retirement. With Roth contributions, you pay tax now, but qualified withdrawals, including all the growth, are tax-free. In both cases the investments grow without yearly tax on dividends or gains, which helps compounding. Social Security and Medicare taxes still apply to your contributions either way. To see how a contribution changes your take-home pay, try our paycheck calculator.

Similar plans exist for other employers: 403(b) plans for schools and nonprofits, governmental 457(b) plans and the federal Thrift Savings Plan. They share the same $24,500 limit in 2026, and this calculator works for them too.

The 2026 contribution limits

The IRS raises the limits most years for inflation. For 2026 the employee deferral limit is $24,500, up from $23,500 in 2025. That cap covers your own contributions across every 401(k), 403(b) and similar plan you have in the year, whether traditional or Roth. If you change jobs mid-year, you must keep the total across both employers under the limit yourself.

A separate limit covers everything that goes into your account in a year from you and your employer together: $72,000 for 2026, not counting catch-ups. Few people reach it unless their employer is very generous or they make after-tax contributions.

Catch-up contributions at 50 and 60 to 63

Once you reach 50 (you only need to turn 50 by December 31), you can put an extra $8,000 into your 401(k) in 2026. The SECURE 2.0 Act added a larger "super catch-up" for people who are 60, 61, 62 or 63 at the end of the year: $11,250 instead of $8,000. At 64 the catch-up drops back to the regular amount.

Catch-ups are useful if you started late, took time out of work, or your income has risen. Your plan must allow them, which nearly all large plans do. The calculator applies the right limit for your age in each year of the projection, so catch-ups start at 50, rise from 60 to 63 and fall back at 64. It keeps the dollar limits at their 2026 levels, so for a long projection it slightly understates what a maximum saver could put in.

The new Roth catch-up rule

From January 1, 2026, higher earners must make their catch-up contributions as Roth. The rule applies if your FICA wages (Social Security wages, box 3 of your W-2) from the employer sponsoring the plan were more than $150,000 in the previous year. For 2026, that means 2025 wages over $150,000. The threshold started at $145,000 in the law and is adjusted for inflation in $5,000 steps.

In practice it means less of an immediate tax cut for affected savers. A 55-year-old in the 32% bracket who puts in the full $8,000 catch-up as Roth pays tax on that $8,000 now instead of saving $2,560 of federal tax this year, but the money and its growth come out tax-free later.

How an employer match works

A match is money your employer adds when you contribute. Plans describe it as a rate and a cap. "50% up to 6%" means 50 cents for every dollar you put in, on contributions up to 6% of your pay. "100% up to 4%" means dollar for dollar on the first 4%.

Some employers also make a non-elective contribution, such as a 3% safe harbor contribution, which you get whether or not you save anything yourself. Enter it under More options. Matches are often paid each pay period, so if you hit the yearly limit early by contributing a high percentage, check whether your plan has a "true-up" or you may lose part of the match.

The cost of missing the match

Contributing 3% when your employer matches 50% up to 6% leaves $1,125 a year of free money unclaimed on a $75,000 salary. Over a career the effect is large, because the missed match would also have grown.

Your own extra 3% accounts for part of that gap and the lost match for the rest. If money is tight, getting to the full match is still usually the first saving goal, ahead of extra payments on low-rate debt.

A worked example

The example assumes pay rises 3% a year, a 7% yearly return before 0.5% fees, and a $20,000 starting balance. Growth makes up more than two-thirds of the final balance: that is compounding at work. In today’s dollars, with 2.5% inflation, the balance is worth about $659,684. Our compound interest calculator shows the same effect for any savings.

How much to contribute

A common rule of thumb is to save about 15% of your pay for retirement, counting your employer’s share. If you can’t start there, many plans offer automatic increases of 1% a year, which you barely notice when they line up with a raise. Our retirement calculator works backward from the income you want to the saving you need.

Why starting early matters

Each decade of delay roughly halves the result, because the money that goes in early has the longest time to compound. Starting at 25 instead of 35 more than doubles the balance at 67 even though only ten extra years of contributions go in.

Fees: the quiet drag

Every fund charges an expense ratio, and some plans add administration fees. They are taken from your balance every year, so they compound against you. The Department of Labor’s guide to 401(k) fees gives an example in which fees just one percentage point higher cut the balance after 35 years by 28%.

Look up the expense ratios on your plan’s fee disclosure. Broad index funds often charge well under 0.1%; actively managed funds often charge 0.5% to 1% or more.

Roth or traditional contributions

The deciding question is whether your tax rate is higher now or in retirement, which nobody knows for sure. Many people split their contributions to keep options open. Employer matches have traditionally gone in as pre-tax money, though plans may now let you take them as Roth. Use our federal income tax calculator to see your bracket, and the Roth IRA calculator to compare tax-free growth outside work.

Vesting and changing jobs

Your own contributions are always 100% yours. Employer contributions may vest over time. A "cliff" schedule gives you nothing until a set date (no more than three years), then everything; a "graded" schedule vests a share each year, reaching 100% by six years at most. Safe harbor contributions usually vest at once.

When you leave a job you have four choices:

• Leave the money in the old plan, if the balance is large enough for the plan to allow it.
• Roll it into your new employer’s 401(k).
• Roll it into an IRA, which often gives a wider choice of cheaper funds.
• Cash it out. This is almost always a mistake: it is taxed as income, usually with a 10% penalty if you are under 59½, and the money stops growing.

Today's dollars and inflation

A balance decades away is in future dollars. At 2.5% inflation, prices more than double in 37 years, so $1,644,822 then would buy about what $659,684buys today. The calculator shows both. Plan with the today’s-dollars figure: it tells you what kind of lifestyle the money would support.

Choosing investments

Most plans offer a target-date fund, which holds a mix of stocks and bonds that becomes more cautious as your retirement year nears. It is a reasonable default if you don’t want to manage the mix yourself. Others offer index funds for US stocks, international stocks and bonds that you can combine.

The 7% default return reflects a long-run, mostly stock portfolio before inflation. Stock-heavy portfolios have fallen by a third or more in bad years. A portfolio with more bonds is steadier but should be expected to earn less; try 5% or 6% to see the difference.

Taking money out

1. Before 59½Income tax plus a 10% penalty

   Unless an exception applies, such as disability or certain medical costs.

2. Age 55Rule of 55

   If you leave your job in or after the year you turn 55, you can take money from that employer's plan without the 10% penalty.

3. 59½Penalty-free withdrawals

   Traditional money is taxed as income; qualified Roth money is tax-free.

4. 73Required minimum distributions

   Traditional balances must start paying out each year; the age rises to 75 for people born in 1960 or later.

401(k) loans and hardship withdrawals

Many plans let you borrow from your own balance, usually up to half of your vested balance or $50,000, whichever is less, repaid through payroll within five years. The interest goes back into your account, but the borrowed money is out of the market while it is lent, and if you leave your job the loan may have to be repaid quickly or be treated as a withdrawal.

Hardship withdrawals are for immediate and heavy financial needs. They can’t be paid back, are taxed, and are usually subject to the 10% penalty. Both are best kept for real emergencies; an emergency fund in a savings account is a better first line of defense.

When you hit the limit

If you max out your 401(k), the usual next steps are an IRA (a Roth IRA if your income allows, $7,500 in 2026 plus $1,100 from age 50), a health savings account if you have a qualifying high-deductible health plan, and then a taxable brokerage account. Some plans also allow after-tax contributions up to the $72,000 total limit, which can be converted to Roth.

Using the calculator well

• Enter your contribution rate and match exactly as your plan documents describe them.
• Add any flat employer contribution, such as a safe harbor 3%, under More options.
• Try a lower return (5%) to see a cautious case, and compare fee levels.
• Read the today’s-dollars figure for planning; the headline figure is in future dollars.
• Copy the link to save your figures and come back after your next raise.

Common mistakes

• Contributing less than the match.
• Leaving old 401(k)s scattered across past employers and forgetting them.
• Cashing out when changing jobs.
• Paying high fees without checking for cheaper index funds in the plan.
• Selling in a panic after a market fall, which locks in the loss.
• Forgetting the limit when you have two employers in one year.

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