401(k) Paycheck Calculator: the real cost of contributing.
Raising your 401(k) deferral does not cut take-home pay by the full amount. Enter your salary, pay frequency and contribution rate to see the net reduction per paycheck, the income tax you defer and the free employer match that lands in your account.
No sign-up, nothing stored. Weekly, biweekly, semi-monthly and monthly pay schedules supported.
401(k) Paycheck Calculator
Live Calculation—
How Much Will a 401(k) Contribution Reduce Your Paycheck?
Less than the contribution itself. A traditional 401(k) deferral comes out of your pay before federal income tax, so part of every dollar you save is money that would otherwise have gone to the IRS. At a 22% bracket, deferring $100 lowers take-home pay by about $78. Add an employer match and the amount landing in your account can be well over the amount leaving your paycheck.
What Does the Paycheck Calculator Not Include?
Pre-tax 401(k) deferrals reduce federal income tax and, in most states, state income tax — but they do not reduce Social Security and Medicare (FICA) tax, which is still charged on the deferred amount. Roth contributions reduce neither: the full deferral comes out of take-home pay. Use your combined federal and state marginal rate for traditional contributions, and 0% to model a Roth deferral.
| Tax | Traditional deferral | Roth deferral |
|---|---|---|
| Federal income tax | Reduced | Not reduced |
| State income tax | Reduced in most states | Not reduced |
| Social Security & Medicare | Not reduced | Not reduced |
How Should You Pick a Contribution Rate?
- Find the match ceilingContribute at least up to the percentage your employer matches — below it you are refusing part of your pay.
- Check the per-paycheck costRaise the slider one point at a time and watch the net reduction, not the gross deferral.
- Escalate automaticallyAdd 1% every January or with each raise until you reach about 15% including the match.
- Stay under the cap$24,500 for 2026, plus catch-ups from age 50; spread it across all pay periods to keep every match dollar.
See what the chosen rate grows into by retirement in the 401(k) growth calculator, or compare tax treatments in the Roth vs traditional calculator.
Paycheck Impact Questions
Why did my paycheck drop less than my 401(k) contribution?
Because traditional deferrals are taken before federal and most state income tax. Your withholding falls at the same time, softening the drop.
Does maxing out early in the year lose the match?
It can. If your plan matches per paycheck without a year-end true-up, hitting the limit in October means no match for November and December.
Is the employer match taxed?
Not when it is paid in. Match dollars are pre-tax and are taxed as income when withdrawn.
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