Self-Employment Tax Calculator (US)

If you are paid on a 1099 form, nobody withholds tax from your income, and you are treated as both employer and employee for Social Security and Medicare. That makes the tax bill larger than many freelancers expect, and it is due in quarterly instalments. This calculator estimates the whole federal bill for tax year 2025 from your net profit, and divides it into four payments.

Self-employment tax

An employee pays 7.65 percent for Social Security and Medicare and the employer pays the same; a self-employed person pays both halves. The page multiplies net profit by 92.35 percent, then applies 12.4 percent for Social Security up to the yearly wage base (176,100 for 2025) and 2.9 percent for Medicare on all of it. If you also have a job, the wages already taxed use up part of the wage base, so the Social Security part shrinks. An extra 0.9 percent Medicare tax applies above the threshold.

Income tax

Half of the self-employment tax is deducted from your income, which the page shows. Then the standard deduction applies: 15,750 for single filers, 31,500 for married filing jointly and 23,625 for head of household. If you leave the qualified business income toggle on, the page takes 20 percent of the smaller of your profit after the half-tax deduction and your taxable income before the deduction. The rest goes through the 2025 brackets for your filing status.

A worked example

The default is net profit of 85,000, single, with no other income. Self-employment tax is 12,010, of which Social Security is 9,734 and Medicare 2,276. Half, 6,005, is deducted. After the standard deduction of 15,750, income is 63,245, and the QBI deduction takes 12,649, leaving taxable income of 50,596. The income tax is 6,045. The total is 18,055, or 21.2 percent of profit, and a quarterly payment of 4,514. For 160,000 of profit, filing jointly with 20,000 of other income, self-employment tax is 22,607, the total is 36,582 and a quarter is 9,145. The side-job case, with 25,000 of profit next to 70,000 of wages, has self-employment tax of 3,532 and a total of 14,471.

Quarterly payments

The table lists four payments of equal size, due April 15, June 15, September 15 and January 15 of the next year, and notes that a date falling on a weekend moves to the next business day. The note also mentions a common safe harbor: paying at least 90 percent of this year’s tax, or 100 percent of last year’s (110 percent if last year’s adjusted gross income was over 150,000), through estimates and withholding, avoids an underpayment penalty.

Edge cases

Earnings after the 92.35 percent factor below 400 produce no self-employment tax, which is the rule’s threshold. A zero profit gives zero tax, and the share-of-profit line shows a dash. The wage base is a field, so you can use a different year’s figure. Wages are used to reduce the Social Security base, to test the additional Medicare threshold and to add to the income that is taxed.

Limits

The page covers federal tax for 2025 only. State and local taxes, credits, the deduction for health insurance, retirement contributions such as a solo 401(k), and the limits that apply to the QBI deduction above about 197,300 for single filers and 394,600 for joint filers, or for certain service businesses, are not modelled. Treat the figures as a planning estimate and confirm with the IRS or a tax professional.

Related tools

• 401(k) Calculator shows how employer-plan savings grow, as a contrast to going solo.
• Profit Margin Calculator turns revenue and costs into the net profit you enter here.
• GST / VAT / Sales Tax handles the tax you may need to charge your customers.
• Salary Calculator converts a freelance hourly rate into a yearly figure.