401(k) Paycheck Calculator

Quick answer: why $100 saved costs less than $100

A traditional (pre-tax) 401(k) contribution comes out of your pay before federal income tax is figured, and in most states before state income tax too. So each dollar you put in lowers your take-home pay by less than a dollar — the difference is income tax you aren't paying this year. Social Security and Medicare are still taken out on the full amount, because pre-tax deferrals still count as wages for those taxes (IRS Topic 424).

Example: a single filer in Texas earning $75,000, paid every two weeks, who saves 6% puts $173.08 into the plan each paycheck. Take-home pay drops by only $135.00. Each dollar saved costs about 78 cents of take-home pay. The same 6% as a Roth contribution cuts take-home by the full $173.08.

How a 401(k) contribution changes your paycheck

The calculator runs your paycheck twice — once without the contribution and once with it — using the same federal withholding method and state rules as our paycheck calculator. The difference is the real cost to your take-home pay.

Contribution − income tax no longer withheld on it = drop in take-home pay

Example: $173.08 − $38.08 = $135.00 per paycheck ($75,000, Texas, 6%).

Contribution (taken after tax) = drop in take-home pay

Example: 6% of $75,000 over 26 paychecks = $173.08 per paycheck.

What a pre-tax contribution does and doesn't reduce

• Reduces: federal income tax withholding, and state income tax in most states.
• Doesn't reduce: Social Security tax (6.2% on wages up to $184,500 in 2026) or Medicare tax (1.45%) (SSA).
• Doesn't reduce in Pennsylvania: Pennsylvania income tax. See state exceptions.

Because the saving comes from your top tax bracket, higher earners and people in high-tax states get a bigger cut in the cost of each dollar. The tables below show how much.

Take-home cost at 3%, 6%, 10% and 15%

These rows come straight from the calculator: single filer, paid biweekly (26 paychecks), traditional contributions, no other deductions. Texas has no state income tax; California does.

In every row the take-home drop is smaller than the contribution, and the gap is wider in California because state income tax is also deferred. Your numbers will differ with filing status, other deductions and where you live, so enter your own details above.

Traditional vs Roth 401(k)

Most Vanguard plans now offer both: Vanguard reports that 98% of its plans offer a Roth option, but only 18% of participants in those plans use it (How America Saves 2026). Here is the paycheck difference at a 6% contribution:

Tax rate now vs later

The "tax deferred now" column isn't a free gift: with a traditional 401(k), withdrawals in retirement are taxed as income. With a Roth, you pay the tax now and qualified withdrawals later are tax-free. The usual way to think about it:

• Traditional tends to suit you if you expect a lower tax rate in retirement than today, or you need the bigger paycheck now.
• Roth tends to suit you if your tax rate is low now (early career, a low-income year) and you expect it to be higher later.
• Splitting between the two is a reasonable hedge if you can't tell. Many plans let you choose a percentage for each.

Nobody knows future tax rates, so treat this as a judgment call rather than a calculation.

The Saver's Credit for lower incomes

If your income is modest, contributing may also earn a federal tax credit. For 2026 the Saver's Credit is available with adjusted gross income up to $40,250 (single), $60,375 (head of household) or $80,500 (married filing jointly). The top 50% credit rate applies below $24,250, $36,375 and $48,500 respectively (Notice 2025-67).

2026 401(k) limits by age

The IRS raised the employee deferral limit to $24,500 for 2026. Catch-up amounts depend on your age at the end of the year (IRS). The same limits apply to 403(b) plans, most governmental 457 plans and the federal Thrift Savings Plan.

A separate cap covers everything that goes into your account from you and your employer combined (not counting catch-ups): $72,000 in 2026 under Section 415(c) (Notice 2025-67). The ages 60–63 "super catch-up" comes from the SECURE 2.0 Act. In the year you turn 64, the catch-up drops back to $8,000.

The calculator caps your contribution at your limit. If the percentage you enter would go over, it shows the capped amount.

The Roth catch-up rule for earners over $150,000

Starting with 2026 contributions, if your FICA wages from the employer that sponsors the plan were more than $150,000 in 2025, any catch-up contributions you make in 2026 must go in as Roth (after tax). Your regular contributions up to $24,500 can still be pre-tax (Notice 2025-67).

The final regulations were issued in September 2025. They are mandatory from 2027, and for 2026 plans may use a reasonable, good-faith reading of the rule (IRS). Some collectively bargained and governmental plans have a later start date. If your plan has no Roth option, high earners generally can't make catch-up contributions at all; the calculator assumes a Roth option exists. Also, the match here is worked out for the whole year — if you front-load contributions and your plan doesn't do a year-end "true-up", you could miss some match.

Example from the calculator: a 61-year-old earning $200,000, whose 2025 wages were $190,000, contributing the maximum of $35,750: $24,500 goes in pre-tax and $11,250 must be Roth. A 61-year-old whose 2025 wages were $140,000 can make the full $35,750 pre-tax ($0 required as Roth).

Getting the full employer match

Vanguard's 2026 report puts the average promised employer match at 4.7% of pay (median 4.0%). The most common single formula — used by 12% of plans — is 50 cents per dollar on the first 6% of pay (Vanguard). Here is what that formula pays on a $60,000 salary:

Contributing 3% instead of 6% leaves $900 a year of match unclaimed. At 6%, the employer adds $1,800 on top of your $3,600. Contributing more than 6% still helps your savings, but it earns no extra match under this formula. Many plans also have a vesting schedule, so check how long you must stay before the match is fully yours.

What typical savers do

In Vanguard's data the average employee deferral rate was 7.6% (median 6.6%), and the average total rate including employer money was 12.1%. Participation averaged 83% of eligible employees (weighted by participant), and 61% of plans enroll new workers automatically. Only 14% of participants contributed the legal maximum.

State exceptions: Pennsylvania and New Jersey

Pennsylvania counts employee contributions to eligible retirement plans as taxable compensation; federal qualified-plan status "is not controlling for PA PIT purposes" (PA Department of Revenue). A 401(k) lowers your federal taxable wages but not your Pennsylvania wages. On a $75,000 salary at 6%, the calculator shows a take-home drop of $135.00 per paycheck in Pennsylvania — the same as in Texas, because only federal tax is deferred in both.

New Jersey doesn't tax 401(k) contributions when made (unless they exceed the federal limit), but it does tax 403(b) and 457 contributions when they're made (NJ GIT-1 & 2, January 2026). If you're a New Jersey teacher or public employee, expect less state tax saving than a 401(k) saver would get.

Other 2026 pre-tax limits: IRA, HSA and FSA

Other paycheck deductions also lower taxable pay. Here are the 2026 limits for context.

Sources: IRA (IRS); HSA (Rev. Proc. 2025-19, §223); health FSA (IRS); dependent care FSA (§129).

Got a raise or a bonus coming? See how it changes your paycheck with the raise calculator and the bonus tax calculator, then decide whether to raise your contribution rate.

Common questions

How much will a 401(k) contribution reduce my paycheck?

Less than the contribution if it's traditional (pre-tax). At $75,000 in Texas, a 6% contribution of $173.08 per biweekly paycheck lowers take-home by $135.00. A Roth contribution lowers take-home dollar for dollar.

What is the 401(k) limit for 2026?

$24,500 in employee contributions; $32,500 if you're 50 or older; $35,750 if you're 60 to 63. Employee plus employer contributions are capped at $72,000, not counting catch-ups.

Are 401(k) contributions subject to Social Security and Medicare tax?

Yes. Pre-tax deferrals skip federal income tax withholding but still count as wages for Social Security (6.2% up to $184,500 in 2026) and Medicare (1.45%).

Do my catch-up contributions have to be Roth in 2026?

Only if your FICA wages from that employer were over $150,000 in 2025. Then your 2026 catch-ups must be Roth; your regular contributions can stay pre-tax.

What is the average 401(k) match?

Vanguard puts the average promised match at 4.7% of pay (median 4%). The most common formula is 50% of what you contribute, on up to 6% of pay.

Does Pennsylvania tax 401(k) contributions?

Yes. Pennsylvania treats employee contributions to eligible retirement plans as taxable compensation, so only your federal tax goes down.

Should I stop contributing to pay off debt?

Many people keep contributing at least enough to get the full match, since it's an immediate return, and put extra cash toward high-interest debt. The debt payoff calculator shows what extra payments save.

Sources

1. 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500 — Internal Revenue Service. Accessed October 13, 2026.
2. Notice 2025-67: 2026 limitations for retirement plans — Internal Revenue Service. Accessed October 13, 2026.
3. Treasury, IRS issue final regulations on new Roth catch-up rule — Internal Revenue Service. Accessed October 13, 2026.
4. Topic no. 424, 401(k) plans — Internal Revenue Service. Accessed October 13, 2026.
5. Contribution and benefit base — Social Security Administration. Accessed October 13, 2026.
6. PA personal income tax guide: gross compensation — Pennsylvania Department of Revenue. Accessed October 13, 2026.
7. GIT-1 & 2: Employee and retiree income (rev. January 2026) — New Jersey Division of Taxation. Accessed October 13, 2026.
8. Revenue Procedure 2025-19: 2026 HSA limits — Internal Revenue Service. Accessed October 13, 2026.
9. 26 U.S. Code § 223 (HSA catch-up) — Legal Information Institute, Cornell Law School. Accessed October 13, 2026.
10. IRS releases tax inflation adjustments for tax year 2026 — Internal Revenue Service. Accessed October 13, 2026.
11. 26 U.S. Code § 129 (dependent care assistance) — Legal Information Institute, Cornell Law School. Accessed October 13, 2026.
12. How America Saves 2026 — Vanguard. Accessed October 13, 2026. 2025 plan data; some figures are Vanguard estimates.