US 401(k) Calculator
Project your retirement savings with employer match and compound growth. 2026 IRS contribution limits.
Contribution details
e.g. 50 = 50¢ per $1
% of your salary
Growth assumptions
Why the 401(k) is the most powerful savings tool in the US
Free employer match
The employer match is an instant 50–100% return on the first dollars you contribute. A 50% match on up to 6% of your salary is worth $2,400/year on an $80k salary — tax-deferred on top of that.
Tax-deferred growth
Traditional 401(k) contributions reduce your current-year taxable income and grow tax-deferred. You pay taxes only at withdrawal in retirement — when you may be in a lower bracket.
Compound interest
At 7% annual return, money doubles roughly every 10 years. Starting at 25 instead of 35 results in more than twice the final balance — the extra decade at the start is the most valuable.
2026 IRS limits
Employee limit: $24,500. Catch-up: $8,000 from age 50, or $11,250 at ages 60–63. The employer-plus-employee limit is $72,000 before catch-up contributions.
The 4% rule
A widely used retirement withdrawal guideline: withdraw 4% of your balance in year 1, adjust for inflation thereafter, and your portfolio should last 30 years. This calculator shows your projected monthly income using this rule.
Roth vs Traditional
Traditional: deduction now, taxes later. Roth: no deduction now, tax-free growth and withdrawal. If you expect to be in a higher bracket in retirement than now, Roth wins. Most people in early career benefit from Roth 401(k) if their employer offers it.
Frequently Asked Questions
How much should I contribute to my 401(k)?
At minimum: whatever gets you the full employer match. If your employer matches 50% on up to 6% of salary, contribute at least 6% — otherwise you leave guaranteed free money. After capturing the full match, the next priority depends on your situation. If you have high-interest debt, pay that first. Otherwise, continue increasing 401(k) contributions up to the limit, especially if you're in a high tax bracket.
What is a good annual return to use for projections?
The US stock market (S&P 500) has returned roughly 10% nominal per year over long periods, but 7% is a more conservative assumption after inflation. For a target-date fund (typical default), 6–7% is a reasonable long-run projection. Higher return assumptions make the projection look better but increase risk of being wrong. We use 7% as the default.
What happens if I leave my job?
You keep 100% of your own contributions. Employer contributions vest on a schedule — immediately (100% vested from day 1), cliff vesting (0% until a milestone, then 100%), or graded (e.g. 20% per year over 5 years). After leaving, you can keep the money in the old 401(k), roll it to a new employer's plan, or roll it to a traditional IRA — all tax-free. Cash out and you owe income tax plus a 10% penalty (before age 59½).
Can I contribute to a 401(k) and an IRA?
Yes. In 2026 the employee 401(k) limit is $24,500 and the IRA limit is $7,500. Roth IRA income limits still apply, and both limits are also capped by the relevant compensation rules.
Understanding Your 401(k)
A 401(k) is an employer-sponsored retirement account that lets you invest a portion of each paycheck before (or after) tax, where it grows for decades. For most American workers it is the single most powerful wealth-building tool available — not because of any one feature, but because of how the employer match, tax treatment, and compound growth stack on top of each other over a career.
The employer match is free money
A typical match is 50% of your contributions up to 6% of salary, or dollar-for-dollar up to a lower percentage. On an $80,000 salary, a 50%-up-to-6% match adds $2,400 a year to your account at no cost to you. That is an instant 50% return before the market does anything. The single most important rule of 401(k) investing is to contribute at least enough to capture the full match — anything less is leaving guaranteed money on the table.
Traditional vs Roth
Traditional 401(k) contributions are made pre-tax: they lower your taxable income now, and you pay tax on withdrawals in retirement. Roth 401(k) contributions are made after-tax: no deduction today, but qualified withdrawals — including all growth — are completely tax-free. The rule of thumb is that if you expect to be in a higher tax bracket in retirement than you are now (common for younger workers early in their careers), the Roth wins; if you are a high earner today expecting lower income later, traditional usually wins.
2026 contribution limits
For 2026 the employee contribution limit is $24,500. The catch-up is $8,000 from age 50, except ages 60–63 can contribute an $11,250 catch-up. The employer-plus-employee limit is $72,000 before catch-up contributions. Roth and traditional 401(k) contributions share the employee cap.
Why starting early matters so much
Compound growth rewards time more than amount. At a 7% annual return, money roughly doubles every decade. A 25-year-old contributing for ten years and then stopping can end up with more at 65 than a 35-year-old who contributes steadily for thirty years — because the early dollars compound through more doubling cycles. This is the core reason financial planners stress starting as young as possible, even with small amounts.
The 4% rule and what the balance means
A widely used retirement guideline is the 4% rule: you can withdraw about 4% of your balance in the first year of retirement, adjust for inflation thereafter, and the portfolio should last roughly 30 years. A $1,000,000 balance translates to about $40,000 a year, or $3,333 a month, of inflation-adjusted income. Viewing your projected balance through this lens turns an abstract number into a concrete monthly retirement income — and often reveals whether your current contribution rate is on track.