Pre-tax retirement savings shrink your taxable income, so each dollar saved costs you less than a dollar of take-home pay.
401(k) rate
Saved per year
Federal tax
Take-home
0%
$0
$13,170
$79,180
5%
$5,000
$12,070
$75,280
10%
$10,000
$10,970
$71,380
15%
$15,000
$9,870
$67,480
With state income tax
State tax depends on where you live. These rows show the effect of a flat rate on top of federal taxes; plug your own state's rate into the paycheck calculator.
About $79,180 for a single filer in a state with no income tax, based on 2026 federal brackets, Social Security and Medicare. That is $6,598.33 a month or $3,045.38 every two weeks.
What tax bracket is $100,000 in?
For a single filer, after the standard deduction the top dollars are taxed at 22%. The average federal income tax rate is much lower, 13.2%, because lower brackets apply first.
How much does a 401(k) save in tax?
Putting 10% ($10,000) into a traditional 401(k) lowers federal income tax by about $2,200 a year for a single filer, so take-home pay drops by less than the amount you save.