Self-Employment Tax Calculator — California 2026

Understanding Self-Employment Tax in California

Self-employment tax is the combined Social Security (12.4%) and Medicare (2.9%) tax that self-employed individuals pay on their net earnings. Unlike W-2 employees who split this 50/50 with their employer, self-employed individuals pay the full 15.3% themselves — though they can deduct half of it from their federal taxable income.

The 2026 Social Security Wage Base

In 2026, the Social Security wage base is $176,100. This means the 12.4% Social Security tax only applies to the first $176,100 of net SE income. The 2.9% Medicare tax applies to all SE income with no cap. An additional 0.9% Medicare surtax applies to income above $200,000 (single) or $250,000 (MFJ).

Reducing Your SE Tax

The most effective strategies for reducing SE tax are: (1) S Corp election to convert some income from SE-taxable to distribution income; (2) maximizing retirement plan contributions to reduce the SE income base; and (3) ensuring all legitimate business expenses are deducted to minimize net SE income.

Frequently Asked Questions

Q: Do I owe SE tax on all 1099 income?
A: SE tax applies to net earnings from self-employment — your 1099 income minus allowable business expenses. Passive income, rental income, and investment income are generally not subject to SE tax.

Q: When do I pay SE tax?
A: SE tax is paid through quarterly estimated tax payments (due April 15, June 15, September 15, and January 15). Underpaying by more than $1,000 triggers a penalty.

Q: Does California have a separate SE tax?
A: No. California does not have a separate SE tax. However, California does charge SDI (State Disability Insurance) at 0.9% on all wages and self-employment income with no wage base cap in 2026.

Related Resources

• Self-Employed Tax Preparation Guide
• Quarterly Estimated Tax Payments
• Retirement Plan Deductions for Self-Employed