How to use the self-employment tax calculator
- 1Enter your expected net profit from self-employment for 2026: business income minus business expenses, as on Schedule C.
- 2If you also have a job, enter your 2026 W-2 wages. They use up part of the Social Security wage base.
- 3Choose your filing status. It only affects the Additional Medicare Tax threshold.
- 4Read your self-employment tax, the Social Security and Medicare parts, the half you can deduct and your effective rate on profit.
What self-employment tax is
Self-employment tax is Social Security and Medicare tax for people who work for themselves. An employee pays 7.65% and the employer pays another 7.65%; when you are self-employed you pay both halves, 15.3% in total: 12.4% for Social Security and 2.9% for Medicare.
It is charged on top of income tax and applies to sole proprietors, independent contractors, freelancers, 1099 workers and members of most partnerships and LLCs taxed as partnerships. You report it on Schedule SE with your Form 1040.
Self-employment tax rate = 12.4% Social Security + 2.9% Medicare = 15.3%
How the tax is worked out
You do not pay the 15.3% on all of your profit. First multiply net profit by 92.35%, which mirrors the employer half an employee never sees in their pay. The result is your net earnings from self-employment. If it is under $400, you owe no self-employment tax.
Social Security tax of 12.4% applies only up to the 2026 wage base of $184,500. Medicare tax of 2.9% has no cap. Because of the 92.35% step, the tax works out at about 14.13% of profit for most people.
Net earnings = Net profit × 92.35% Social Security = 12.4% × the lower of (Net earnings, $184,500 − W-2 wages) Medicare = 2.9% × Net earnings Self-employment tax = Social Security + Medicare
W-2 wages, the wage base and Additional Medicare Tax
If you also have a job, your W-2 wages count toward the $184,500 Social Security wage base first. Only the part of the base that is left is charged the 12.4% on your self-employment earnings. If your wages are $184,500 or more, you pay only the 2.9% Medicare part on your self-employment earnings.
Additional Medicare Tax of 0.9% applies to wages and self-employment earnings above $200,000 for single and head of household filers, $250,000 for married filing jointly and $125,000 for married filing separately. These thresholds are fixed in law and not adjusted for inflation. It is figured on Form 8959, is not part of self-employment tax and is not deductible, so the calculator shows it separately.
Additional Medicare Tax = 0.9% × (Net earnings − (Threshold − W-2 wages, not below 0)), if positive
The deductible half, and where these figures come from
You can deduct half of your self-employment tax when working out adjusted gross income. It lowers your income tax but not the self-employment tax itself. On $60,000 of profit the deduction is $4,238.87, which saves $508.66 of income tax in the 12% bracket.
The 2026 wage base of $184,500 is from the Social Security Administration. The rates, the 92.35% factor and the $400 minimum are from the IRS’s Schedule SE instructions and Topic 554, and the Additional Medicare Tax thresholds from Topic 560, all checked November 2026. This calculator covers federal self-employment tax only; for income tax and quarterly payments use the quarterly tax calculator.
Deductible part = Self-employment tax ÷ 2
Worked example
A single freelance designer expects $60,000 of net profit in 2026 and has no other job.
| Net profit | $60,000.00 |
| Net earnings (× 92.35%) | $55,410.00 |
| Social Security (12.4%) | $6,870.84 |
| Medicare (2.9%) | $1,606.89 |
| Self-employment tax | $8,477.73 |
| Effective rate on profit | 14.13% |
| Deductible half | $4,238.87 |
The designer owes $8,477.73 of self-employment tax on top of income tax. If they also earned $160,000 in W-2 wages and $50,000 of profit, only $24,500 of the wage base would be left: Social Security tax would be $3,038.00 and Medicare $1,339.08, for $4,377.08 in total.