401(k) calculator 2027

What a 401(k) really costs you

A traditional 401(k) contribution comes out of your pay before federal income tax (and state tax in most states), so a $100 contribution costs you less than $100 of take-home pay. Social Security and Medicare are still taken from it. A Roth 401(k) contribution comes from taxed pay, so it costs the full amount now, but qualified withdrawals in retirement are tax-free.

Example: $80,000 salary, 6% in, 50% match up to 6%

• You put in: $4,800 a year, or $400 a month.
• Cost from your paycheck: $3,744 a year (single, no state income tax), because you save $1,056 of federal tax at 22%.
• Employer match: $2,400, so $7,200 a year goes into your 401(k) for $312 a month of take-home pay.
• At 65: starting with $25,000 at 35, growing 6% a year with 0.3% fees and 3% raises, it could be worth about $435,000 in today’s money, or about $913,000 in future dollars.
• Contributing only 3% would cost $156 a month but lose $1,200 a year of free match money.

401(k) limits for 2026

• Employee contributions: $24,500, traditional and Roth together.
• Catch-up from age 50: a further $8,000, so $32,500 in total.
• Ages 60 to 63: a higher catch-up of $11,250, so $35,750 in total.
• Roth catch-up rule: from 2026, if you earned more than $150,000 from your employer in 2025, your catch-up contributions must go in as Roth.
• Everything together: your contributions plus your employer’s can’t pass $72,000 (plus catch-up).
• IRA: $7,500, or $8,600 from age 50.
• 2027 limits: the IRS normally announces them in mid-November. We’ll add them as soon as they’re published; until then the 2027 option uses the 2026 limits.

Traditional or Roth?

• Traditional usually wins if your tax rate now is higher than it will be in retirement, for example in your peak earning years.
• Roth usually wins early in your career, in a low bracket, or if you expect higher taxes later. Roth money also has no required minimum distributions from a 401(k).
• Splitting between the two gives you a choice of which pot to draw from each year in retirement.

Getting money out

Withdrawals before 59½ usually cost a 10% penalty on top of income tax, with some exceptions, such as leaving your job in or after the year you turn 55. Required minimum distributions from traditional accounts start at 73. A common rule of thumb is that drawing 4% of your pot a year gives an income that lasts about 30 years; Social Security comes on top.

To see your full paycheck, use the US paycheck calculator. This calculator assumes the standard deduction and no other income. It doesn’t cover vesting schedules, true-up matches or the $72,000 overall limit. Growth is not guaranteed.