401(k) Paycheck Calculator

Thinking about raising your 401(k) contribution? See what it really costs per paycheck after the tax savings, plus how much your employer adds.

Updated October 28, 2026Checked against IRS Pub 15-T & state tables2026 limit $24,500

Your 401(k) impact

You contribute / paycheck: $161.54
Take-home drops by: $128.69
Taxes saved / year: $854
Employer match / year: $2,100
Total into 401(k) / year: $6,300
Cost per $1 saved: $0.80

Every $100.00 you put in your traditional 401(k) only costs you about $79.67 of take-home pay, because it skips federal and state income tax. Social Security and Medicare still apply.

Why 401(k) contributions cost less than they look

A traditional 401(k) contribution comes out of your pay before federal income tax is figured. If you're in the 22% bracket, each $100 you contribute cuts your federal withholding by $22. In a state with income tax you save even more. The money still counts for Social Security and Medicare, so FICA stays the same.

2026 retirement plan limits

401(k), 403(b), most 457 plans	$24,500
Catch-up, age 50+	$8,000
Super catch-up, ages 60–63	$11,250
IRA	$7,500
HSA (self / family)	$4,400 / $8,750
Health FSA	$3,400

Pennsylvania taxes traditional 401(k) contributions at the state level, and New Jersey and California tax HSA contributions. The calculator applies these rules automatically.

Frequently asked questions

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

Less than you think. Traditional 401(k) contributions come out before federal and (in most states) state income tax, so contributing $100 typically lowers take-home pay by only $70–$88. The calculator shows your exact cost per paycheck.

What is the 401(k) contribution limit for 2026?

$24,500 for employee deferrals. Workers 50 and older can add an $8,000 catch-up, and those aged 60–63 can add $11,250 instead. From 2026, catch-up contributions for people who earned over $150,000 the prior year must go into a Roth account.

Do 401(k) contributions reduce Social Security and Medicare taxes?

No. Traditional 401(k) deferrals are still subject to FICA (7.65%). Only Section 125 benefits like health insurance, HSA and FSA contributions avoid FICA.

Traditional or Roth 401(k)?

Traditional lowers your tax now and you pay tax on withdrawals in retirement. Roth costs more in your paycheck today but grows tax-free. If you expect a higher tax rate in retirement, or you’re early in your career, Roth often wins. Many people split contributions between the two.

How much should I contribute to get the full match?

At least enough to get your employer’s full match. A common formula is 50% of what you contribute up to 6% of salary, so contributing 6% earns a 3% match. Contributing less leaves free money on the table.