Self-Employment Tax Calculator

Self-Employment Tax Calculator works out the Social Security and Medicare tax that freelancers, contractors and sole proprietors owe on their own earnings — the tax an employer would normally split with you. Enter net self-employment income and the tool applies the 92.35% net-earnings adjustment, then charges 12.4% for Social Security up to the annual wage base and 2.9% for Medicare with no ceiling, plus the 0.9% Additional Medicare Tax above the statutory threshold. Because W-2 wages consume part of the Social Security wage base first, there is a field for them so someone with both a job and a side business is not overcharged. The result includes the deductible half of SE tax, which reduces your income tax bill separately, and a suggested quarterly estimated payment so you know what to send the IRS each quarter. All figures use the current-year FICA wage base, shown as a visible tax-year label.

Key Features

• Correct 92.35% Net Earnings Base

  Applies the statutory adjustment that removes the employer-equivalent half of FICA before tax is charged. Skipping this step is the single most common error in DIY SE tax math.

• Social Security Wage Base Cap

  Stops charging the 12.4% Social Security portion once earnings reach the annual wage base. The Medicare portion continues uncapped, exactly as the law works.

• W-2 Wage Coordination

  Enter wages from a regular job and the tool reduces the remaining Social Security wage base accordingly. Anyone with a salary plus freelance income needs this to avoid double-counting.

• Additional Medicare Tax

  Adds the 0.9% surtax on combined earnings above the filing-status threshold. The threshold is statutory and never inflation-adjusted, so it catches more filers each year.

• Deductible Half Shown Separately

  Displays the half of SE tax you can deduct against income tax, so the figure is ready to carry to your return. It is not netted into the headline number, which is what you actually pay.

• Quarterly Estimate

  Divides the annual liability into a suggested quarterly estimated tax payment. Useful for setting up a recurring transfer rather than facing one bill in April.

1. 1

   Enter your net self-employment income

   Use profit after business expenses, not gross revenue. This is the figure from Schedule C line 31.

2. 2

   Add any W-2 wages

   If you also have a salaried job, enter those wages so the Social Security wage base is not double-counted.

3. 3

   Choose your filing status

   This sets the Additional Medicare Tax threshold, which differs between single, married jointly, and married separately filers.

4. 4

   Read the summary cards

   Check total SE tax, the suggested quarterly payment, and the effective rate against your net income.

5. 5

   Note the deductible half

   Carry the deductible half of SE tax to your income tax return, where it reduces adjusted gross income.

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