Self-Employment Tax Calculator

Last updated: October 2026

How is self-employment tax calculated in the US? It is 15.3 percent on 92.35 percent of net self-employment earnings: 12.4 percent for Social Security, capped at the annual wage base, plus 2.9 percent for Medicare with no cap, plus 0.9 percent Additional Medicare above the filing-status threshold. Half is deductible against income tax.

What is self-employment tax?

Self-employment tax is how freelancers, contractors and sole proprietors in the US pay into Social Security and Medicare. Employees split these taxes with their employer; when you work for yourself you pay both halves, at a combined rate of 15.3% on 92.35% of your net profit.

This calculator works out your full self-employment tax bill for the 2025 or 2026 tax year: the Social Security part with its annual wage base cap, the Medicare part, the 0.9% Additional Medicare Tax at higher incomes, the half of the tax you can deduct against income tax, and the quarterly estimated payment you should be sending the IRS. If you also have a job, enter your W-2 wages and the calculator applies the shared Social Security wage base the way Schedule SE does, instead of double-counting the cap.

Rates last reviewed: October 2026. Figures are taken from the IRS and the Social Security Administration; sources are listed at the bottom of this page.

How to use it

1. Enter your net self-employment profit: your business income after expenses, the profit figure from Schedule C. Do not use your total revenue.
2. Choose the tax year, 2026 or 2025. The year sets the Social Security wage base ($184,500 for 2026, $176,100 for 2025).
3. Choose your filing status. It sets the threshold for the 0.9% Additional Medicare Tax.
4. If you also have a job, enter your W-2 wages. Social Security tax was already withheld on them, so they use up the wage base first; leave the field at 0 if you have no W-2 job.
5. Read the breakdown: your taxable SE earnings, the Social Security and Medicare parts, any Additional Medicare Tax, your total self-employment tax, the deductible half, and what to pay each quarter.

What it calculates and how the formulas work

• Taxable SE earnings = net profit × 92.35%. The tax is charged on this reduced figure, not on your full profit (see below for why).
• Social Security tax = 12.4% × the smaller of your taxable SE earnings and the wage base left after W-2 wages. The wage base is $184,500 for 2026 and $176,100 for 2025, so the largest possible Social Security part in 2026 is $22,878.
• Medicare tax = 2.9% × taxable SE earnings. There is no cap on the Medicare part.
• Additional Medicare Tax = 0.9% × taxable SE earnings above your filing-status threshold, after W-2 wages have used up the threshold first. Thresholds: $200,000 single or head of household, $250,000 married filing jointly, $125,000 married filing separately (Form 8959).
• Total self-employment tax = Social Security + Medicare + Additional Medicare Tax.
• Deductible half = half of the Social Security + Medicare parts. You deduct it when working out adjusted gross income, so it lowers your income tax. It never lowers the self-employment tax itself, and the 0.9% Additional Medicare Tax is not included in it.
• Quarterly estimated payment = total self-employment tax ÷ 4, the amount to build into each quarterly estimated tax payment.

Why the tax applies to 92.35% of your profit

Employees pay Social Security and Medicare tax on their wages, and their employer pays a matching amount on top. Nobody pays tax on the employer’s half. To put the self-employed in the same position, the IRS lets you exclude the employer-equivalent share (7.65%) from the earnings the tax is charged on. What is left is 100% minus 7.65%, which is 92.35% of your net profit. It is a built-in reduction, not a discount you have to claim separately: Schedule SE applies the 0.9235 factor for you, and so does this calculator.

Worked examples

Example 1: $50,000 profit, 2026, single, no W-2 job. Taxable SE earnings are $50,000 × 92.35% = $46,175. Social Security is $46,175 × 12.4% = $5,725.70. Medicare is $46,175 × 2.9% = $1,339.08. Total self-employment tax: $7,064.78, an effective rate of 14.13% of profit. The deductible half is $3,532.39, and each quarterly estimated payment is $1,766.19.

Example 2: $100,000 profit, 2026, single. Taxable SE earnings are $92,350, still under the wage base, so the full 15.3% applies: total self-employment tax is $14,129.55. Half of it, $7,064.78, is deductible against income tax.

Example 3: $200,000 profit, 2026, single. Taxable SE earnings are $184,700, which is over the 2026 wage base, so the Social Security part is capped at $184,500 × 12.4% = $22,878. Medicare has no cap: $184,700 × 2.9% = $5,356.30. Taxable earnings are still under the $200,000 Additional Medicare threshold, so no 0.9% tax applies. Total self-employment tax: $28,234.30.

Paying it: quarterly estimated taxes

There is no employer withholding when you are self-employed, so the IRS expects you to pay this tax during the year in four estimated instalments, due in mid-April, mid-June, mid-September and the following mid-January, using Form 1040-ES. The quarterly figure in your result is the self-employment tax share of each payment; most people owe estimated income tax on top and pay both together. Our guide to quarterly estimated taxes for freelancers walks through the dates, the safe-harbor rules and how to avoid underpayment penalties.

Important considerations and limitations

• This calculator covers self-employment tax only. Federal income tax comes on top of it, and most states charge their own income tax as well. Neither is included here.
• The Additional Medicare Tax follows the Form 8959 approach (threshold measured against W-2 wages plus SE income combined), simplified to the two income figures you enter. If you have several W-2 jobs, or Medicare wages that differ from your Social Security wages, your Form 8959 result can differ.
• Self-employment tax is generally due only when your net earnings from self-employment reach $400 (measured after the 92.35% factor). Below that, the calculator flags it and still shows the figures for reference. The IRS optional methods, which some low earners use to build Social Security credits, are not modelled.
• Special rules that are not covered: ministers and members of religious orders, church employees, nonresident aliens, and people with an approved exemption from SE tax (Form 4361 or Form 4029).
• If you run more than one business, the IRS combines the profits on a single Schedule SE. Add your businesses together and enter the combined profit.
• Figures are estimates based on the rates in force for 2025 and 2026. This is not tax advice; check your position with a qualified tax professional or the IRS before filing.

Frequently asked questions

What is the self-employment tax rate for 2026?

15.3%, made up of 12.4% for Social Security and 2.9% for Medicare. It is charged on 92.35% of your net self-employment earnings, not on the full amount. The Social Security part only applies up to the 2026 wage base of $184,500 of earnings; the Medicare part has no cap, and a further 0.9% Additional Medicare Tax applies above the filing-status thresholds.

Why is self-employment tax charged on 92.35% of my profit?

Employees never pay tax on the employer’s matching share of Social Security and Medicare. To match that treatment, self-employed people exclude the employer-equivalent 7.65% from the earnings the tax is charged on, leaving 92.35%. Schedule SE applies this 0.9235 factor automatically.

What is the Social Security wage base for 2026?

$184,500, up from $176,100 in 2025 (Social Security Administration). Only earnings up to that combined total of W-2 wages plus SE earnings are charged the 12.4% Social Security part, so the most Social Security tax anyone pays in 2026 is $22,878. Medicare tax continues on all earnings above the base.

How do I pay self-employment tax?

Through quarterly estimated taxes, using Form 1040-ES, in four instalments due in mid-April, mid-June, mid-September and mid-January, together with your estimated income tax. The tax itself is reported on Schedule SE when you file your annual return, and the estimates you paid are credited against the total. See our guide to quarterly estimated taxes for the dates and safe-harbor rules.

Can I deduct half of my self-employment tax?

Yes. Half of the Social Security and Medicare parts is an above-the-line deduction that reduces your adjusted gross income, so it lowers your income tax. Two limits matter: it never reduces the self-employment tax itself, and the 0.9% Additional Medicare Tax is not part of the deductible half.

Do I owe self-employment tax if my profit is under $400?

Generally no. The tax applies when your net earnings from self-employment are $400 or more, and net earnings are measured after the 92.35% factor, so a profit of about $434 is where the tax starts to bite. Under the threshold you may still want to look at the IRS optional methods, which let some low earners build Social Security credits voluntarily.

Related tools and guides

Selling on marketplaces or platforms instead? Work out what each platform keeps before self-employment tax is even due: the Fiverr Fee Calculator, Upwork Fee Calculator and Etsy Fee Calculator. For the payments side, read the guide to quarterly estimated taxes for freelancers.

Sources: IRS, “Self-employment tax (Social Security and Medicare taxes)” (irs.gov); Social Security Administration, “Contribution and Benefit Base” (ssa.gov); IRS Form 8959 (Additional Medicare Tax) and Schedule SE.