401(k) Paycheck Impact Calculator
Deferring 6% of your salary does not cost you 6% of your take-home pay — it costs less, because the contribution comes out before income tax. This calculator shows the real cost per paycheck and what the employer match adds on top.
Tax year 2026 · Updated 2026-08-29 · Federal, state and local withholding · Free, no sign-up
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What a contribution really costs
A traditional 401(k) deferral reduces your federal and state income tax wages but not your Social Security and Medicare wages. So the saving is your combined marginal income tax rate, not your full tax rate. In a 22% federal bracket with a 5% state rate, every $100 deferred reduces take-home pay by about $73.
The table shows a $80,000 salary in a state with no income tax, where the saving is federal only.
| Contribution rate | Annual contribution | Take-home pay reduction | Tax saved | Cost per $1 saved |
|---|---|---|---|---|
| 3% | $2,400 | $1,872 | $528 | $0.78 |
| 5% | $4,000 | $3,120 | $880 | $0.78 |
| 6% | $4,800 | $3,744 | $1,056 | $0.78 |
| 10% | $8,000 | $6,240 | $1,760 | $0.78 |
| 15% | $12,000 | $9,360 | $2,640 | $0.78 |
2026 contribution limits
The elective deferral limit for 401(k), 403(b) and most 457(b) plans is $24,500 for 2026. If you are 50 or older you may add a catch-up of $8,000. Under SECURE 2.0 there is a larger super catch-up of $11,250 for the calendar years in which you turn 60, 61, 62 or 63 — it does not apply from 64 onward, and plans are not required to offer it.
The employer match does not count against your elective deferral limit; it sits under a much higher combined limit. What it does have is a schedule, and missing it is the most expensive mistake in retirement saving. If your employer matches 50% of the first 6% of pay, contributing 5% leaves half a percent of your salary on the table every year.
Traditional or Roth?
A traditional deferral cuts your tax now and is taxed on withdrawal. A Roth deferral gives you no deduction now and comes out tax-free later. The textbook rule is to choose traditional if you expect a lower rate in retirement and Roth if you expect a higher one.
State tax complicates it in ways people miss. Pennsylvania taxes 401(k) contributions on the way in and exempts qualified distributions entirely, which makes the traditional deduction worth less there. Illinois does the reverse — full deduction going in, no tax coming out — which makes a traditional deferral unusually powerful. The Roth comparison calculator models both.
Frequently asked questions
How much will a 401(k) contribution reduce my paycheck?
Less than the contribution itself. Because the deferral escapes federal and state income tax, a $100 contribution typically reduces take-home pay by $70 to $80 depending on your bracket and state. Social Security and Medicare still apply to the deferred amount.
What is the 401(k) limit for 2026?
$24,500 in elective deferrals, plus an $8,000 catch-up if you are 50 or older, or an $11,250 super catch-up in the years you turn 60 to 63 if your plan offers it.
Does my employer match count toward the limit?
Not toward the $24,500 elective deferral limit. It counts toward a separate, much higher overall contribution limit that most people never approach.
Should I contribute enough to get the full match?
Almost always, yes. An employer match is an immediate return on the contribution that no investment can reliably beat. Contributing below the match threshold is declining part of your compensation.