Self-Employment Tax Calculator

The self-employment tax calculator estimates the Social Security and Medicare taxes contractors and sole proprietors owe on their net business profit. Unlike a W-2 employee whose employer splits these payroll taxes, self-employed contractors pay both the employee and employer share — a combined 15.3% rate.

This calculator applies the standard 92.35% net earnings factor, the 12.4% Social Security rate (up to the annual wage base), and the 2.9% Medicare rate, then shows your total liability and quarterly estimated payment.

Start with your net profit from self-employment, then multiply by 92.35% to get your taxable net earnings (this accounts for the employer-equivalent portion of SE tax). Social Security tax applies at 12.4% up to the annual wage base cap; Medicare applies at 2.9% with no cap (plus an additional 0.9% Medicare surtax above high income thresholds, not included here).

You can deduct half of your total SE tax as an adjustment to income on your federal return, which lowers your overall taxable income even though it does not reduce the SE tax itself.

• Track every deductible expense: Tools, vehicle mileage, home office, and materials all reduce net profit before SE tax applies.
• Consider an S-Corp election: At higher income levels, splitting income into salary and distributions can lower SE tax exposure — consult a tax professional.
• Pay quarterly estimates on time: Avoid IRS underpayment penalties by paying roughly a quarter of your estimated annual tax every quarter.
• Fund a SEP-IRA or Solo 401(k): Retirement contributions lower taxable income, though not SE tax itself.