2026 Self-Employment Tax Calculator

How self-employment tax is calculated

First subtract eligible expenses to find business profit. Under the regular Schedule SE method, multiply profit by 92.35%. If these net earnings reach $400, apply 12.4% Social Security tax within your remaining 2026 wage base and 2.9% Medicare tax to all adjusted earnings.

Your own Social Security wages and reported tips (W-2 boxes 3 + 7) reduce the $184,500 limit; your spouse’s wages never use your limit. Additional Medicare Tax is 0.9% of adjusted earnings above the remaining threshold after Medicare wages: $200,000 single or head of household, $250,000 joint, or $125,000 separate. Joint returns combine both spouses’ Medicare wages.

Worked example

With $50,000 net profit and no W-2 wages, a single filer has $46,175 adjusted net earnings. Social Security tax is $5,725.70 and Medicare tax is $1,339.08: $7,064.78 combined. The deductible half is $3,532.39. No Additional Medicare Tax applies.

Does $400 of profit trigger self-employment tax?

The $400 test applies after the 92.35% adjustment. $400 profit becomes $369.40 net earnings and produces no regular-method SE tax. $434 profit becomes $400.80 net earnings and crosses the threshold. When it applies, tax covers all adjusted earnings, rather than only the excess over $400.

What this tool includes

This is the Social Security and Medicare tax on one person’s ordinary Schedule C profit. It excludes federal income tax and Additional Medicare Tax already attributable to W-2 wages. Use the 1099 tax calculator to add ordinary federal income tax and payments. The standard deduction and QBI deduction do not lower SE tax; Additional Medicare Tax is not part of the deductible half.

Business losses, spouse self-employment, optional farm/nonfarm methods, clergy, church employees, railroad wages, exemptions and international agreements are unsupported. These estimates keep cents and may differ from whole-dollar tax-return rounding. Enter projected annual wages across all jobs. Blank money fields mean zero.

2026 rules and sources

• IRS Topic 554: self-employment tax and Schedule SE instructions describe the regular method and deductible half.
• IRS Publication 15 (2026) gives the $184,500 Social Security wage base.
• Form 8959 instructions provide the 0.9% Additional Medicare Tax and wage coordination. These thresholds are not indexed.

Method guidance currently references 2025 instructions; the 2026 wage base comes from the 2026 publication. Reviewed October 6, 2026. All assumptions and sources.