Self-Employed Retirement Contribution Calculator

2026 tax year

Estimate your maximum Solo 401(k) and SEP IRA contribution side by side, as a sole proprietor or an S-corp owner, and how much federal income tax a Traditional contribution could save you.

Try an example

Your numbers

How your business is taxed

Your business profit after expenses, before any retirement contribution.

$

Optional. The employee deferral limit is shared across every 401(k)/403(b) you participate in, so a day job's plan reduces what you can defer here.

$

For the tax savings estimate

Optional. W-2 wages (yours or your spouse's), interest, and so on.

$

Optional. Customer tips shown separately on a 2026 Form 1099-NEC, 1099-MISC or 1099-K, for the tips deduction. Tips not included in a 1099 don't count, whether they were paid in cash, by card or through an app.

$

Only matters above about $201,750 of taxable income ($403,500 joint), where the QBI deduction phases out. Service businesses lose it faster. Not sure? Keep the first choice, which gives the higher tax.

Estimated maximum contribution

Solo 401(k)

$0

Employee deferral
$0
Employer contribution
$0
Federal income tax saved
$0
Cost after tax savings
$0

SEP IRA

$0

Employer contribution
$0
Federal income tax saved
$0
Cost after tax savings
$0

How the numbers are figured
    This calculator gives a general estimate for educational purposes only. It isn't personalized financial or tax advice. The tax savings figure is federal income tax only: it leaves out state tax, credits and itemized deductions, and assumes the whole contribution is Traditional (Roth contributions don't lower this year's tax). It doesn't cover every situation (multiple businesses, plan-specific rules, prior-year corrections). Confirm your actual limit with a CPA or your plan provider before contributing. Read the full Financial Disclaimer.

    Related guides

    Sources

    The official, primary sources behind the figures and rules on this page.

    1. 1IRS: Notice 2025-67, 2026 amounts relating to retirement plans and IRAs (PDF)
    2. 2IRS: 401(k) limit increases to $24,500 for 2026 (IR-2025-111)
    3. 3IRS: COLA increases for dollar limitations on benefits and contributions
    4. 4IRS: One-Participant 401(k) Plans
    5. 5IRS: Self-employed individuals — calculating your own retirement plan contribution and deduction
    6. 6IRS: Self-employment tax (Social Security and Medicare taxes)
    7. 7IRS Topic no. 554, Self-employment tax
    8. 8IRS: Retirement plans FAQs regarding SEPs
    9. 9IRS: Retirement topics — catch-up contributions
    10. 10IRS: Rev. Proc. 2025-32, 2026 inflation-adjusted items incl. section 199A thresholds (PDF)
    11. 11IRS: Instructions for Form 8995 (QBI deduction)
    12. 12IRS: Schedule 1-A (Form 1040), Additional Deductions (PDF)