401(k) Paycheck Impact Calculator

How to do it

1. 1
   Step 1: Open 401(k) Paycheck Impact Calculator and add your input

   Type your numbers or text, add your file, or pick the options you need. Nothing is uploaded: everything stays in your browser.

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   Step 2: What 401(k) Paycheck Impact Calculator does

   See how a 401(k) contribution changes your take-home pay, tax and employer match.

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   Step 3: Read the result and compare

   The result appears at once. Change one value to see how the answer moves, then keep the figure that fits your case.

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   Step 4: Copy or save it

   Copy the result or download it. For an important decision, confirm it with the official source or an adviser.

About this tool

Enter your gross pay per paycheck, how often you are paid, the percentage you want to contribute and your employer's match. The tool applies the IRS limit for your age, then shows the contribution per paycheck, the tax you save and how little your take-home pay actually falls.

The idea

Pre-tax 401(k) money is taken before income tax, so a $350 contribution lowers a paycheck by much less than $350. At a 27% combined rate it costs $255.50. Social Security and Medicare tax still apply to the full pay.

Limits (2026)

Employee deferrals are limited to $24,500, plus $8,000 if you are 50 or older, or $11,250 if you are 60 to 63. The total including the employer share is limited to $72,000 for 2026 ($70,000 in 2025).

The match

The match is worked out as a percentage of what you contribute, up to a cap that is a percentage of your pay (for example 50% of the first 6%). Vesting rules can delay when the match is yours, which is not modeled here.

Worked example

$3,500 paid twice a month ($84,000 a year), 10% contributed, a 50% match on the first 6%, 22% federal and 5% state tax: you contribute $350 per paycheck ($8,400 a year), save $2,268 in tax, receive $2,520 of match, and take-home pay falls by only $255.50 per paycheck.

Tips for best results

Check every box before you rely on a result, because one wrong digit changes the whole answer. Use the exact figures from your payslip, bill, certificate or contract, and keep a note of the date you calculated. Rates, thresholds and rules change from time to time, so for tax, fees and legal matters treat the output as an estimate and confirm with the official source named on this page. You can run as many scenarios as you like; nothing is saved or sent, and refreshing the page clears the boxes.