How this calculator works
Self-employment (SE) tax is the Social Security and Medicare tax for people who work for themselves. An employee splits these taxes with an employer. A freelancer or sole owner pays both halves. The calculator follows the steps on Schedule SE.
- Start with net profit. Enter your net self-employment profit. That is business income minus business expenses, usually from Schedule C.
- Apply the 92.35% step. Multiply net profit by 92.35%. This mirrors the fact that employees don’t pay FICA on the employer’s share. If the result is under $400, SE tax is zero.
- Social Security part. Multiply by 12.4%, but only up to the 2026 wage base of $184,500. If you also have W-2 wages, those use up the wage base first.
- Medicare part. Multiply the full amount by 2.9%. There is no cap.
- Additional Medicare Tax. Add 0.9% on the amount above your filing-status threshold. The threshold is reduced by any W-2 wages.
- Extras. The results show half of SE tax, which you can deduct from income, and SE tax divided by four as a quarterly figure.
That quarterly figure covers SE tax only. Federal income tax on the same profit is extra. The federal income tax calculator can estimate it.
2026 self-employment tax figures at a glance
| Item | 2026 figure |
|---|---|
| Share of net profit subject to SE tax | 92.35% |
| Social Security rate | 12.4% up to $184,500 |
| Medicare rate | 2.9%, no cap |
| Additional Medicare Tax | 0.9% over $200,000 single/HoH, $250,000 joint, $125,000 separate |
| Minimum net earnings for SE tax | $400 |
| Quarterly estimate due dates (2026 tax) | Apr 15, Jun 15, Sep 15, 2026 and Jan 15, 2027 |
The rates and rules are summarized in IRS Tax Topic 554. The 2026 wage base comes from the Social Security Administration.
Worked example
Full-time freelancer with $60,000 profit
- Net earnings: $60,000 × 92.35% = $55,410
- Social Security: $55,410 × 12.4% = $6,870.84
- Medicare: $55,410 × 2.9% = $1,606.89
- SE tax: $6,870.84 + $1,606.89 = $8,477.73
- Deductible half: $8,477.73 ÷ 2 = $4,238.87
- Quarterly SE tax: $8,477.73 ÷ 4 = $2,119.43
The effective SE tax rate on profit is about 14.1%, not the full 15.3%, because of the 92.35% step.
Side business on top of a $170,000 job
Alex is single, earns $170,000 in W-2 wages and makes $40,000 of net profit from consulting.
- Net earnings: $40,000 × 92.35% = $36,940
- Wage base left: $184,500 − $170,000 = $14,500
- Social Security: $14,500 × 12.4% = $1,798.00
- Medicare: $36,940 × 2.9% = $1,071.26
- Additional Medicare threshold left: $200,000 − $170,000 = $30,000, so 0.9% × ($36,940 − $30,000) = $62.46
- Total: $1,798.00 + $1,071.26 + $62.46 = $2,931.72
- Deductible half (excluding Additional Medicare): ($1,798.00 + $1,071.26) ÷ 2 = $1,434.63
Because Alex’s job already used most of the Social Security wage base, only $14,500 of the side income faces the 12.4% rate.
Common self-employment tax mistakes
- Forgetting SE tax applies even with low income tax. A freelancer can owe zero income tax after the standard deduction and still owe SE tax on every dollar of profit above the $400 floor.
- Using gross receipts. SE tax is based on profit after business expenses. Business mileage is one common expense; the mileage calculator totals it at the 2026 rates.
- Ignoring W-2 wages. If you also have a job, your wages count toward the $184,500 cap. Leaving them out can overstate SE tax.
- Missing quarterly payments. No employer withholds for you. The IRS may charge a penalty if you pay too little during the year. Form 1040-ES has the worksheet.
- Expecting tips or overtime deductions to cut SE tax. The new OBBBA deductions reduce income tax only. Social Security and Medicare still apply.
Our guide on how self-employment tax works goes deeper into the half-SE-tax deduction and estimated payments.
How SE tax and income tax fit together
Self-employed people pay two separate federal taxes on the same profit. SE tax funds Social Security and Medicare. Income tax is based on your brackets after deductions. The two are figured differently but paid together on Form 1040.
The half-SE-tax deduction links them. In the $60,000 example, $4,238.87 comes off income before the standard deduction. That lowers income tax, but it does not lower SE tax itself. Business expenses, by contrast, lower both, because they reduce the profit that both taxes start from.
When planning quarterly payments, add your estimated income tax to the SE figure. Then divide the total across the four due dates. The IRS Form 1040-ES page has the worksheet and payment options.
What this calculator doesn’t include
- Federal income tax on your profit, which is owed on top of SE tax.
- State and local taxes, including any local self-employment or business taxes.
- The optional methods on Schedule SE for farm and low-income years.
- Church employee income and other special cases.
- The qualified business income deduction and other income tax deductions.
- Penalties for underpaying estimated tax.
For your actual return, check the Schedule SE instructions or ask a tax professional. The paycheck calculator shows the employee side of the same taxes.