Traditional 401(k) contributions are made with pre-tax dollars, reducing your federal taxable income. For 2026, you can contribute up to $24,500 (or $32,500 if you are age 50 or older with the $8,000 catch-up contribution). Use this calculator to see how much you save in federal income tax by contributing to your 401(k). Note: this estimates federal income tax savings only, employer match is not modeled.
How 401(k) Tax Savings Work
Pre-Tax Contributions
When you make traditional (pre-tax) 401(k) contributions, the money is deducted from your paycheck before federal income tax is calculated. This directly reduces your taxable income. For example, if you earn $85,000 and contribute $10,000, your W-2 will show only $75,000 in taxable wages (Box 1).
Contribution Limits
For 2026, the IRS limits employee elective deferrals to $24,500. Workers age 50 and older can contribute an additional $8,000 as a catch-up contribution, bringing the total to $32,500. These limits apply across all 401(k) plans you participate in during the year.
Tax Savings by Bracket
Your tax savings depend on your marginal tax bracket. If your last dollar of income falls in the 22% bracket, each dollar contributed to your 401(k) saves you approximately $0.22 in federal income tax. If your contribution crosses bracket boundaries, the savings rate varies across the contribution amount.
What's Not Included
This calculator estimates federal income tax savings only. It does not model state income tax savings (which would increase your total savings), employer matching contributions, FICA taxes (which are not reduced by 401(k) contributions), or the long-term growth benefit of tax-deferred investing.
Worked Examples
Example 1: Moderate Contribution, $10,000
Profile: Single filer, $85,000 salary, age 35, $10,000 contribution
Federal tax without 401(k): $9,870.00 Federal tax with 401(k): $7,670.00 Tax savings: $2,200.00 Contribution as % of salary: 11.8% Effective "discount" rate: 22.0%
Example 2: Max Contribution, $24,500
Profile: Single filer, $120,000 salary, age 40, max $24,500 contribution
Federal tax without 401(k): $17,570.00 Federal tax with 401(k): $12,180.00 Tax savings: $5,390.00 Contribution as % of salary: 20.4% Effective "discount" rate: 22.0%
Example 3: Catch-Up Contribution, Age 55
Profile: Single filer, $85,000 salary, age 55, $32,500 contribution (with $8,000 catch-up)
Max contribution (50+): $24,500 + $8,000 = $32,500 Federal tax without 401(k): $9,870.00 Federal tax with 401(k): $4,120.00 Tax savings: $5,750.00 Contribution as % of salary: 38.2% Effective "discount" rate: 17.7%
Frequently Asked Questions
What is the 401(k) contribution limit for 2026?
The employee elective deferral limit for 2026 is $24,500. If you are age 50 or older, you can contribute an additional $8,000 as a catch-up contribution, for a total of $32,500.
How do 401(k) contributions reduce my taxes?
Traditional (pre-tax) 401(k) contributions reduce your taxable income dollar for dollar. For example, if you earn $85,000 and contribute $10,000, you are only taxed on $75,000 of income (plus your standard deduction). The tax savings depend on your marginal tax bracket, the higher your bracket, the more you save per dollar contributed.
What is the catch-up contribution for workers 50 and older?
Workers age 50 and older can contribute an additional $8,000 beyond the standard $24,500 limit, for a total of $32,500 in 2026. This catch-up provision allows older workers to accelerate their retirement savings.
Does this calculator account for employer match?
No. This calculator estimates the federal income tax savings from your employee contributions only. Employer matching contributions are a separate benefit, they do not reduce your taxable income (they are not included in your W-2 wages) and are subject to separate overall plan limits.
What about Roth 401(k) contributions?
Roth 401(k) contributions are made with after-tax dollars and do not reduce your current taxable income. The benefit of Roth contributions is that qualified withdrawals in retirement are tax-free. This calculator models traditional (pre-tax) contributions only.
Do 401(k) contributions reduce FICA taxes?
No. Traditional 401(k) contributions reduce your federal and state income tax but do not reduce Social Security or Medicare (FICA) taxes. Your full salary is subject to FICA regardless of how much you contribute to your 401(k).
Can I contribute to both a 401(k) and an IRA?
Yes. The 401(k) limit ($24,500) and IRA limit ($7,500) are separate. However, if you are covered by a 401(k) at work, your ability to deduct traditional IRA contributions may be limited based on your income. Roth IRA contributions have separate income limits.
When should I max out my 401(k)?
Generally, you should contribute at least enough to get your full employer match (free money). Beyond that, maxing out your 401(k) at $24,500 makes sense if you are in a high tax bracket now and expect to be in a lower bracket in retirement. If you expect higher income in retirement, consider Roth contributions instead.
401(k) Contribution Tax Savings Calculator
Federal Tax Savings$2,200.00
Contributing $10,000.00 to your 401(k) saves you approximately $2,200.00 in federal income tax.
Line
Value
Annual Salary
$85,000.00
401(k) Contribution
$10,000.00
Contribution as % of Salary
11.8%
Max Allowed (under 50)
$24,500.00
Federal Tax Without 401(k)
$9,870.00
Federal Tax With 401(k)
$7,670.00
Tax Savings
$2,200.00
Effective "Discount" Rate
22.0%
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