Self-Employment Tax Calculator: How Much Will You Owe in 2026?

What the 15.3% actually covers

Self-employment tax is 12.4% for Social Security plus 2.9% for Medicare. An employee pays half of each through payroll and the employer pays the other half. When you work for yourself, you are both, so you pay the full 15.3%.

It applies to 92.35% of your net profit, not the whole thing. The Social Security piece stops at the annual wage base, the Medicare piece never does, and an extra 0.9% Medicare tax starts above $200,000 of earnings ($250,000 married filing jointly). The calculator uses the 2026 figures for all three.

The half you get back

Half of your self-employment tax is deductible from your income before income tax is calculated, the same way an employer deducts its share. Most self-employed people also get the 20% qualified business income deduction on top. That is why the income tax number on the next page is smaller than a straight bracket lookup would suggest.

The lever that shrinks it

Deductions lower income tax, but the only thing that materially lowers self-employment tax is changing what it applies to. As an S-corp, it applies to the salary you pay yourself and not to the rest of the profit. Above roughly $80,000 of profit the savings usually clear the cost of running payroll, and the calculator on the next page shows your number.