401(k) Contribution Calculator 2025
See how your 401(k) contribution affects your paycheck, how much your employer match adds, and your total annual tax savings — before you decide how much to contribute.
Without 401(k)
With 401(k)
* Simplified estimate. Does not include FICA (7.65%), benefits deductions, or local taxes.
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How This Calculator Works
Traditional 401(k) contributions are pre-tax — they reduce your taxable income before federal and state taxes are calculated. This means every dollar you contribute actually costs you less than a dollar out of pocket.
- Contribution amount — your % × annual salary = annual 401(k) contribution (capped at IRS limit).
- Employer match — employer match % × your contribution, up to the match cap % of salary.
- Tax savings — your contribution × (federal rate + state rate) = taxes you avoid this year.
- Net paycheck cost — your per-paycheck contribution minus the tax savings per paycheck.
Employer Match = min(Contribution × Match%, Salary × MatchCap%)
Tax Savings = Contribution × (Federal Rate + State Rate)
Net Cost per Paycheck = (Contribution − Tax Savings) ÷ Pay Periods
The 2025 IRS contribution limit is $23,500 for employees under 50, and $31,000 for those 50 and older (the extra $7,500 is the “catch-up contribution”). Employer contributions do not count toward this limit.
Frequently Asked Questions
How much should I contribute to my 401(k)?
The baseline rule: contribute at least enough to capture your full employer match — that is an immediate 50–100% return on your money. Beyond that, financial planners commonly recommend saving 10–15% of gross income for retirement. If you started late, aim for 20%+. Use this calculator to see the real paycheck impact before deciding.
What is the 401(k) contribution limit for 2025?
For 2025, the IRS allows employees to contribute up to $23,500 to a 401(k) plan. If you are age 50 or older, you can add a catch-up contribution of $7,500, bringing your total limit to $31,000. These limits apply to your contributions only — employer matching contributions are separate and do not count toward your limit.
Does a 401(k) contribution really reduce my paycheck by the full amount?
No — and this is the key insight most people miss. Because 401(k) contributions are pre-tax, they reduce your taxable income. If you’re in the 22% federal bracket and your state taxes 5%, every $100 you contribute only reduces your take-home pay by about $73. The other $27 was going to taxes anyway.
What does “employer match” mean and how does it work?
An employer match is free money your company adds to your 401(k) when you contribute. A common match is “100% of your contribution up to 6% of your salary” — meaning if you earn $70,000 and contribute 6% ($4,200), your employer adds another $4,200. Not contributing enough to capture the full match is leaving part of your compensation on the table.
What is the difference between a traditional and Roth 401(k)?
A traditional 401(k) uses pre-tax dollars — you get a tax break now, but pay taxes on withdrawals in retirement. A Roth 401(k) uses after-tax dollars — no tax break now, but withdrawals in retirement are tax-free. This calculator covers traditional (pre-tax) contributions. Roth contributions do not reduce your current taxable income.
Can I change my 401(k) contribution at any time?
In most cases, yes. Most employers allow you to change your contribution percentage at any time through your HR portal or plan administrator, with changes taking effect on the next or following paycheck. There is no IRS rule limiting how often you can adjust your contribution rate — only your employer’s plan rules apply.