This calculator projects your 401(k) balance at retirement from your savings, monthly deposits, return and years left. For 2026, the IRS lets you defer up to $24,500 of pay, and more once you're 50. Deposits compound monthly, and the total is shown before tax.
What goes in the monthly box?
Enter everything that reaches the account each month: your own deferral plus any employer match. Both are invested the same way, so the calculator treats them as one deposit.
If you defer a percentage of pay, turn it into dollars first. Say you earn $60,000 and defer 6%. That's $3,600 a year, or $300 a month. The IRS's own example of a match is 50 cents for each dollar you defer. Suppose your plan pays it on deferrals up to 6% of pay. That adds $150, so you'd enter $450.
Your pay stub shows your deferral. The match formula and the vesting rules are in your plan's summary plan description.
How much can you put in for 2026?
The IRS announced the 2026 limits on November 13, 2025. Divide by 12 for the monthly figure the calculator asks for:
| Limit for 2026 | Per year | Per month |
|---|---|---|
| Your own deferrals, under 50 | $24,500 | $2,041.67 |
| Age 50 or older, with the $8,000 catch-up | $32,500 | $2,708.33 |
| The years you turn 60 to 63, with the $11,250 catch-up | $35,750 | $2,979.17 |
| You plus your employer, catch-up aside | $72,000 | $6,000 |
The $24,500 covers your own deferrals only. The same cap applies in 403(b) plans, governmental 457 plans and the federal Thrift Savings Plan. If you work for a school or a nonprofit, the 403(b) calculator fits your plan. Matching money counts toward the $72,000 overall limit instead.
Catch-ups are open to you if you're 50 or older by year-end and your plan offers them. One rule is new for 2026, in plans with a Roth option. If your wages from that employer topped $150,000 last year, your catch-up must go in as Roth money. The calculator won't flag an amount above these limits, so check yours against the table.
Every deposit compounds from the month it lands
P is your current balance and M the monthly deposit. The monthly rate i is the yearly return divided by 12, and n counts the months. Each deposit arrives at the end of its month and keeps growing until you retire.
So your early deposits do most of the work. A deposit made 35 years out compounds for 420 months. One made in your final year gets 12 months at most.
What a 50-cent match adds over 35 years
Here's the $60,000 salary from above, at an assumed 6% a year:
| What goes in each month | Monthly amount | Paid in over 35 years | Balance after 35 years |
|---|---|---|---|
| Your 6% of a $60,000 salary | $300 | $126,000 | $427,413 |
| Your 6% plus the 50-cent match | $450 | $189,000 | $641,120 |
| Your 10% plus the same $150 match | $650 | $273,000 | $926,062 |
The match pays in $63,000 over 35 years ($150 × 12 × 35). By retirement it's worth $213,707, the gap between the first two rows. Defer less than the match formula needs, and you leave part of that money on the table.
Check the vesting rules as well. Your own deferrals are always 100% yours. Employer money may vest over years of service; the IRS example is 20% after two years. Safe harbor 401(k) plans vest employer contributions as soon as they're made. If you might leave early, run the calculator with and without the match.
Catching up after 50
Say you're 50, have $200,000 saved and plan to stop working at 65. Here are those 15 years at 6%, leaving out employer money:
| From 50 to 65, no employer money | Monthly amount | Balance at 65 |
|---|---|---|
| $12,000 a year | $1,000 | $781,637 |
| The regular limit, $24,500 a year | $2,041.67 | $1,084,575 |
| Limit plus the $8,000 catch-up | $2,708.33 | $1,278,452 |
The catch-up adds $120,000 of deposits ($8,000 × 15) and $193,877 to the final balance. In the years you turn 60 to 63, the catch-up rises to $11,250. That's $3,250 more a year, or $13,000 over the four years. The calculator takes one monthly figure, so this table leaves that step out.
The total is before tax, fees and inflation
Traditional deferrals and their gains aren't subject to federal income tax until they leave the plan. So the balance is a pre-tax sum, and part of it will go in income tax. Your deferrals still pay Social Security and Medicare tax when you earn them. Roth deferrals follow the Roth IRA rules instead.
Fees and inflation shrink the total, too. Here's the $450-a-month case once more:
| Same $450 a month for 35 years | Return entered | Balance shown |
|---|---|---|
| 6% a year, no fees counted | 6% | $641,120 |
| Fund fees take 0.5% a year | 5.5% | $571,916 |
| Fund fees take 1% a year | 5% | $511,242 |
| 6% return, at today's prices with 2% inflation | 3.92% | $404,232 |
Fund fees come straight off the return, so enter your return after fees. A 1% fee costs $129,878 in this case. For a result at today's prices, enter the real return: (1.06 ÷ 1.02) − 1 = 3.92%. That assumes your deposits rise with prices each year.
Cashing out early costs extra
Take money out before age 59½ and you may owe a federal 10% additional tax on top of income tax. One exception covers leaving your job in or after the year you turn 55. Changed jobs and got a payout? You have 60 days to roll it into a traditional IRA or another plan. Done in time, the rollover isn't taxed.
Later in life, the rules flip and require minimum withdrawals each year. The RMD calculator works out that amount from your balance and the IRS factor for your age.
Sources
- IRS, 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500 (IR-2025-111, November 13, 2025)
- IRS, Retirement topics – 401(k) and profit-sharing plan contribution limits (updated April 8, 2026)
- IRS, Retirement topics – Catch-up contributions (updated July 5, 2026)
- IRS, 401(k) Resource Guide – Plan participants – 401(k) plan overview
- IRS, 401(k) Resource Guide – Plan participants – General distribution rules