How this calculator works
Self-employment tax is the Social Security and Medicare tax that an employer and employee would split, paid in full by the self-employed: 15.3% on 92.35% of net profit (12.4% Social Security up to the 2026 wage base of $184,500, shared with any W-2 wages, plus 2.9% Medicare on all of it). Income tax is separate. Half the self-employment tax is deductible when you figure adjusted gross income.
- Net earnings from self-employment = net profit × 92.35%.
- Social Security = 12.4% × net earnings, up to the 2026 wage base of $184,500 minus any W-2 wages.
- Medicare = 2.9% × all net earnings, plus 0.9% Additional Medicare Tax on wages and net earnings above $200,000 ($250,000 joint, $125,000 separate).
- Deductible half = (Social Security + Medicare) ÷ 2. No self-employment tax is due when net earnings are under $400.
Worked example
With these inputs: net self-employment profit $50,000; w-2 wages this year $0; filing status Single.
The result is 2026 self-employment tax $7,064.78, with net earnings (92.35% of profit) $46,175.00 and social security part (12.4%) $5,725.70. Self-employment tax comes on top of income tax. The 1099 tax calculator adds both together and gives a set-aside percentage.
Why it's 15.3% (and why it's really about 14.1%)
Employees pay 7.65% of their wages to Social Security and Medicare, and their employer pays another 7.65%. When you work for yourself you pay both halves: 15.3%. It's charged on 92.35% of your profit (which mirrors the employer half being deductible for a business), so the tax works out to about 14.13% of profit, as in the example.
Self-employment tax is on top of income tax. The 1099 tax calculator adds the two together, includes the qualified business income deduction, and turns the total into a set-aside percentage for each payment you receive.
The 2026 wage base and a day job
The 12.4% Social Security part stops once wages and self-employment earnings together reach $184,500 for 2026. If you also have a W-2 job, your wages use up the wage base first, so enter them: a side business on top of a $180,000 salary pays Social Security on only $4,500 of earnings. Medicare's 2.9% has no cap.
How much is due at different profit levels: $25,000 of profit means $3,532.39 of self-employment tax, $100,000 means $14,129.55, and $200,000 means $28,234.30 (the Social Security part stops growing above the wage base).
Lowering self-employment tax legally
Every legitimate business expense lowers net profit, and so lowers both self-employment and income tax: business mileage, a home office, equipment, software, phone and internet for the business. Keep receipts and a mileage log. Health insurance premiums and retirement contributions (SEP-IRA, solo 401(k)) lower income tax but not self-employment tax.
Pay the tax through the year with the quarterly estimated tax calculator; set the money aside in a separate account each time you're paid, and the April bill is already covered.
Sources
Frequently asked questions
How much is self-employment tax in 2026?
15.3% of 92.35% of your net profit: 12.4% Social Security (on up to $184,500 of earnings) plus 2.9% Medicare. On $50,000 of profit that's $7,064.78.
How do I calculate self-employment tax?
Multiply net profit by 0.9235 to get net earnings, then multiply by 15.3% (only 2.9% on earnings above the $184,500 wage base). $50,000 × 0.9235 = $46,175.00; × 15.3% = $7,064.78.
Is self-employment tax deductible?
Half of it is. You subtract half of the self-employment tax ($3,532.39 in the example) from income when figuring adjusted gross income, which lowers your income tax, not the self-employment tax itself.
Do I pay self-employment tax if I made under $400?
No. If net earnings from self-employment are under $400, no self-employment tax is due, though the income still goes on your return.
Do I pay self-employment tax and income tax?
Yes, both. Self-employment tax covers Social Security and Medicare; income tax is figured separately at your bracket on the profit after the deductible half and the QBI deduction.