2026 Calculator
401(k) Contribution Calculator 2026 - Tax Savings Estimator
Free 401(k) tax savings calculator for 2026. See how contributing up to $24,500 ($32,500 if 50+) to your 401(k) reduces your federal income tax. Estimates tax savings by marginal bracket.
401(k) Contribution Calculator 2026: Tax Savings Estimator
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 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 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)
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%