Tax Calculator
Business Retirement Contributions
Find your maximum deductible retirement contribution for 2026 — and see how much it reduces your tax bill this year.
$72,000
2026 maximum contribution (SEP-IRA / Solo 401k)
37%
Maximum marginal rate avoided on each dollar contributed
April 15
Deadline to fund a SEP-IRA for the prior tax year — extended to October 15 if the return is extended
Business Structure & Plan Type
SEP-IRA
Up to 25% of compensation, max $72,000 (2026). Employer contributions only — no employee deferrals. Simplest to set up.
Best for: Sole proprietors and self-employed with high income and no employees.
Income & Personal Info
Schedule C net profit (after expenses, before SE tax deduction)
Age 50+ qualifies for catch-up contributions
Used to estimate your marginal tax rate
Assumptions (2026): Estimates use 2026 federal rates published by the IRS in Rev. Proc. 2025-32: standard deduction $16,100 single / $32,200 joint, Social Security wage base $184,500, self-employment tax 15.3% (12.4% Social Security + 2.9% Medicare). Figures do not include state tax, AMT, the additional 0.9% Medicare surtax, or the qualified business income deduction.
Contribution caps are the 2026 amounts from IRS Notice 2025-67: $24,500 elective deferral, $8,000 age-50 catch-up, $11,250 enhanced catch-up at ages 60-63, $72,000 annual addition limit, $17,000 SIMPLE deferral. Compensation is capped at $360,000 under section 401(a)(17).
Figures last reviewed September 2026.