How to use the 401(k) calculator
- Enter your age, the age you plan to retire, your salary and your current 401(k) balance.
- Enter what you contribute as a percent of pay. Count pre-tax and Roth 401(k) money together.
- Enter your employer match in two parts. A plan that pays “50% of the first 6%” is a match of 50 that stops at 6. A plan that pays “dollar for dollar up to 4%” is 100 and 4. Your benefits portal or plan summary lists the formula.
- Pick an expected return. The default is 7% a year, a common planning figure for a stock-heavy mix after fees. Try 5% too, to see a more cautious case.
Under Raises, inflation and limits you can change the yearly raise (3% by default), the inflation rate used for the today’s-dollars figure, and switch the IRS limits off if you want to model a plan without them.
The 401(k) calculator caps your contribution at the 2026 IRS limit for your age, every year, and warns you if your percentage runs into it. It also tells you if you are leaving employer match on the table.
401(k) contribution limits for 2026
The IRS raised most retirement plan limits for 2026 in Notice 2025-67, published in November 2025.
| Limit | 2025 | 2026 |
|---|---|---|
| Your 401(k), 403(b), 457 or TSP deferrals | $23,500 | $24,500 |
| Catch-up, age 50 and older | $7,500 | $8,000 |
| Catch-up, ages 60 to 63 (instead of the age-50 catch-up) | $11,250 | $11,250 |
| Total from you and your employer (excluding catch-ups) | $70,000 | $72,000 |
| Pay that can count toward contributions | $350,000 | $360,000 |
| IRA contribution limit | $7,000 | $7,500 |
| IRA catch-up, age 50 and older | $1,000 | $1,100 |
So the most a worker under 50 can defer in 2026 is $24,500. From 50 to 59 it is $32,500, from 60 to 63 it is $35,750, and from 64 on it drops back to $32,500. The age that counts is the age you reach by December 31.
New for 2026: if your FICA wages from your employer were more than $150,000 in 2025, your catch-up contributions must go in as Roth (after-tax) money. Your first $24,500 can still be pre-tax. Plans that offer no Roth option cannot accept catch-ups from those workers at all.
The employer match: the best return you will ever get
A match is extra pay that only shows up if you contribute. With a typical 50% match on the first 6% of pay, every dollar you put in up to 6% earns an instant 50 cents before any investment return.
Here is the same 35-year-old from the example at the top: $75,000 salary, $50,000 already saved, 3% raises, 7% return, retiring at 65. Only the contribution rate changes.
| You contribute | Employer match over 30 years | Balance at 65 | In today’s dollars |
|---|---|---|---|
| 3% of pay | $53,522 | $831,961 | $396,631 |
| 6% of pay | $107,045 | $1,283,309 | $611,808 |
| 10% of pay | $107,045 | $1,684,508 | $803,077 |
| 15% of pay | $107,045 | $2,186,006 | $1,042,162 |
Moving from 3% to 6% costs about $2,250 more a year from this worker’s paycheck at the start, before the tax break, and adds roughly $451,000 at retirement. Half of the free match was being left behind at 3%: $1,125 in the first year alone.
Check your plan’s vesting schedule too. Your own contributions are always yours, but matched money can take up to a few years to vest. Leave before then and you may lose some of it.
How much should you have in your 401(k)?
A widely used rule of thumb from Fidelity counts all your retirement savings, not just one 401(k), as a multiple of your salary:
| By age | Saved, as a multiple of salary | On a $75,000 salary |
|---|---|---|
| 30 | 1x | $75,000 |
| 40 | 3x | $225,000 |
| 50 | 6x | $450,000 |
| 60 | 8x | $600,000 |
| 67 | 10x | $750,000 |
Treat these as signposts, not pass-or-fail grades. Someone with a pension, a paid-off house or a later retirement date needs less. Someone planning to retire at 55 needs more.
The calculator’s last line turns your projected balance into income with the 4% rule: withdraw 4% of the balance in the first year of retirement, then adjust for inflation. For the default example, that is about $32,000 a year, or $2,677 a month, in today’s dollars, before taxes and on top of Social Security.
Traditional or Roth 401(k)?
Most plans now offer both, and the calculator’s balance is the same either way. The difference is when you pay tax:
- Traditional (pre-tax): contributions lower your taxable income now. Withdrawals in retirement are taxed as income. Better if you expect a lower tax rate in retirement than today.
- Roth (after-tax): no tax break today, but qualified withdrawals, including all the growth, are tax-free. Better if you expect your tax rate to be the same or higher later, and useful for younger workers in low brackets.
Splitting contributions between the two is a reasonable hedge if you are unsure. The employer match goes into the traditional side unless your plan allows Roth matching. For money outside the plan, the Roth IRA calculator applies the 2026 IRA limit of $7,500.
Why a half-point in fees matters
Fund expenses come straight out of your return. In the default example, a 7% return grows to $1,684,508 by 65. Knock half a percentage point off for fees, to 6.5%, and the balance is $1,531,480. That half-point costs about $153,000 over 30 years.
Look up the expense ratio of each fund in your plan. Broad index funds often charge well under 0.2% a year. If your plan’s options are expensive, contribute enough to get the full match, then compare with an IRA for extra savings.
Taking money out: early withdrawals and RMDs
- Before 59½: withdrawals are usually taxed as income plus a 10% additional tax. Exceptions include separating from your employer in or after the year you turn 55, total disability, certain medical costs and some emergency withdrawals.
- Loans: many plans let you borrow up to half your vested balance, to a maximum of $50,000. You pay the interest back to yourself, but the borrowed money misses out on market growth while it is out.
- Required minimum distributions: withdrawals must start at 73 for people reaching that age now, rising to 75 for those born in 1960 or later. The RMD calculator works out the yearly minimum.
How this 401(k) calculator works
Each year, the calculator works out your contribution as a percent of that year’s salary, caps it at the limit for the age you reach that year, then figures the employer match on what you put in, up to the match limit. Your contribution and the match go in monthly, and the balance grows each month at the monthly equivalent of your yearly return. Your salary rises by the raise percentage at the end of each year.
Two simplifications to know about. First, limits stay at 2026 levels for every future year; in reality they usually rise with inflation, so long projections are a little conservative. Second, the projection is before taxes and ignores loans, hardship withdrawals and job changes. It is a planning estimate, not a guarantee of returns.
Want to see how much of your future balance comes from compounding alone? The compound interest calculator shows the same math without the plan rules. If you are deciding between jobs, the salary to hourly calculator helps you compare offers on equal terms. Run your own numbers and save the link to check again after your next raise.