California (CA) Self Employment Tax Calculator

California has nine income tax brackets ranging from 1% to 12.3%, plus a 1% Mental Health Services surtax on income above $1,000,000 — making the top effective rate 13.3%, the highest in the United States. For a single self-employed person earning $80,000 net profit, the marginal California rate is 9.3% after the $5,706 standard deduction. Source: California FTB.

Yes. California taxes CA Adjusted Gross Income (CA AGI), which approximates federal AGI for self-employed people. Deducting half of SE tax on your federal return reduces federal AGI, which flows through to reduce CA AGI and therefore California taxable income. On $80,000 of SE profit, the deductible half (~$5,652) reduces CA taxable income by the same amount, saving roughly $525 in CA income tax.

No. California does not levy a separate self-employment tax equivalent to federal SE tax. California taxes your net self-employment profit as ordinary income through its regular income tax brackets. Only the federal government imposes the 15.3% SE tax for Social Security and Medicare.

Self-employment (SE) tax is the Social Security and Medicare tax paid by freelancers, 1099 contractors, and sole proprietors. Employees split these costs with their employer (7.65% each); when you work for yourself you pay both halves — 15.3% total — on 92.35% of your net profit. It is separate from, and on top of, federal and state income tax.

Yes. In addition to federal SE tax, California taxes self-employment net profit as ordinary income. This calculator shows both: the federal SE tax (Social Security + Medicare) and the estimated California state income tax side by side, so you can see your true combined tax bill.

Yes — from federal income tax. You can deduct one half of your Social Security and Medicare SE tax as an above-the-line adjustment to income on Form 1040. This deductible half also reduces your federal AGI, which in turn reduces your state taxable income in most states (except Pennsylvania, which taxes gross compensation regardless).

SE tax is based on net profit (gross revenue minus business expenses), so every legitimate business deduction reduces both your SE tax and your state income tax. Common deductions include home-office use ($5/sqft simplified method), equipment and software (Section 179), business mileage, and professional services. The standard deduction and QBI deduction reduce income tax only — not SE tax.

SE tax is paid through quarterly estimated payments (Form 1040-ES), due April 15, June 16, September 15, and January 15 for the prior year's fourth quarter. If you expect to owe $1,000 or more in federal tax after withholding, you generally must pay quarterly to avoid the IRS underpayment penalty. Most states that tax SE income have parallel quarterly estimated payment requirements.