What Is the Self-Employment Tax Calculator?
A self-employment tax calculator estimates the SECA tax owed on 1099 and freelance income. Unlike employees, the self-employed pay both halves of Social Security and Medicare — a combined 15.3% — though half is deductible.
How to use this calculator
Type your numbers into the fields above. The results change the moment you edit any input, so you can try one scenario after another and see exactly what moves. Most calculators show a short summary of the key figures, a line-by-line breakdown underneath, and — where it applies — a year-by-year schedule you can export to a spreadsheet. Everything runs in your browser; nothing is stored or sent anywhere. Treat the output as a planning estimate, not as final word on a real decision.
The Formula
SECA applies 15.3% to 92.35% of net self-employment profit (the equivalent of the employer half). Social Security is 12.4% up to the wage base and Medicare 2.9%, with an extra 0.9% on high earners. The calculator also shows the 50% that is deductible from income tax.
Worked Example
Net profit of $60,000 yields a taxable base of $55,410, and SECA tax near $8,478. Half of that, about $4,239, is deductible against your income tax — a meaningful offset for solo workers.
Tips for the Most Accurate Estimate
- Set aside roughly 25–30% of profit for federal tax plus SECA.
- Make quarterly estimated payments to avoid penalties.
- Track business expenses to lower net profit legally.
- A Solo 401(k) or SEP IRA can reduce taxable income.
- Remember the deductible half lowers your income tax too.
Frequently Asked Questions
Q: Why 92.35% of profit?
Because the employer half of payroll tax is a deduction for employees; for the self-employed, only 92.35% of profit is subject to SECA to mirror that treatment.
Q: Is any of it deductible?
Yes, one half of the SECA tax is deductible when computing your federal income tax, lowering your overall bill.
Q: Do I pay this on top of income tax?
Yes. SECA is separate from income tax, though the deductible half reduces the income taxed. Both are usually paid via quarterly estimates.