Self-Employment Tax Calculator 2026

What is self-employment tax?

Self-employment tax funds Social Security and Medicare for people who earn income from self-employment. If you run a business or work for yourself, this tax is separate from federal income tax. It can affect how much of your business profit is available for pricing, hiring, borrowing, and personal spending.

The calculation starts with your net profit, not your gross business receipts. The calculator applies the self-employment tax rules to 92.35% of that profit. The Social Security portion is 12.4% up to the 2026 wage base of $184,500. The Medicare portion is 2.9%. Additional Medicare tax of 0.9% may apply above the threshold for your filing status, counting wages first.

Why self-employment tax matters

A profitable business can still face a significant tax bill. Estimating self-employment tax helps you set aside cash, decide what to charge, and avoid treating all business profit as spendable income. If you are planning to borrow or make a large purchase, include expected taxes in your cash-flow plan.

The calculator also estimates the deduction for half of the Social Security and Medicare portion of your self-employment tax. That deduction is used when figuring income tax; it does not reduce the self-employment tax itself. Additional Medicare tax is not included in the half deduction.

Your W-2 wages can change the Social Security part of the estimate because they use up some or all of the wage base. Wages also count toward the Additional Medicare tax threshold. Because this is a tax estimate, confirm your situation with a qualified tax professional.

How to use this self-employment tax calculator

1. Enter your net self-employment profit. Use business profit after allowable business expenses, rather than total sales or gross receipts.
2. Enter W-2 wages from a job, if you have them. These wages reduce the remaining Social Security wage base available for self-employment earnings and count toward the Additional Medicare tax threshold.
3. Choose your filing status. The Additional Medicare thresholds are $200,000 for single filers, $250,000 for joint filers, and $125,000 for married filing separately.
4. Review the total tax, its Social Security and Medicare components, the effective rate on profit, and the estimated half deduction. Use the results for planning, then confirm your tax figures with a qualified professional.

Self-employment tax example

How to read your self-employment tax results

Net earnings subject to tax shows the amount after applying the 92.35% calculation to your net profit. Social Security and Medicare are displayed separately so you can see which parts make up the total. The Social Security amount depends on how much of the $184,500 wage base remains after W-2 wages.

Additional Medicare tax is shown separately because it depends on your filing status and combined wages and self-employment earnings. The half deduction applies to the Social Security and Medicare portion, not Additional Medicare tax. The effective rate compares the total self-employment tax with your business profit; it is not your overall tax rate because it does not include income tax.

How to manage your self-employment tax

1. 01

   Keep business records current

   Record income and business expenses as they occur. Review invoices, receipts, and bank transactions so your profit estimate reflects your actual business activity. Accurate records can help you avoid overstating profit or overlooking valid expenses.

2. 02

   Build taxes into your cash plan

   Set aside cash for expected taxes instead of treating every client payment as available income. Revisit your estimate when profit or W-2 wages change, and consider whether your pricing covers both operating costs and taxes.

3. 03

   Check decisions before spending

   A business expense can reduce profit, but spending money only to reduce tax can leave you with less cash overall. Before buying equipment or changing your business plans, compare the cost with the business value and ask a tax professional how the expense is treated.

4. 04

   Review your income mix

   If you have both self-employment income and a W-2 job, keep the wage information current in your estimate. W-2 wages can affect the Social Security portion and the Additional Medicare tax calculation, so a change in either income source can change the result.

Common self-employment tax mistakes

• Entering gross receipts instead of profit

  The calculator needs net self-employment profit after allowable business expenses. Entering total customer payments can overstate the amount used in the calculation.

• Leaving out W-2 wages

  If you have wages from a job, include them. They use up part of the Social Security wage base and count toward the Additional Medicare tax threshold.

• Treating the half deduction as a tax credit

  The deduction reduces income used to figure income tax. It is not a dollar-for-dollar reduction in your tax bill, and it does not reduce self-employment tax.

• Assuming this is your full tax bill

  The estimate covers self-employment tax, not your complete federal tax picture. Your income tax and other circumstances may affect what you owe.

The self-employment tax formula

Key terms

Net self-employment profit

Business profit after allowable business expenses, before applying the self-employment tax calculation.

Net earnings subject to tax

The amount used in the calculation after applying 92.35% to net self-employment profit.

Social Security wage base

The limit on earnings subject to Social Security tax. For 2026, the supplied wage base is $184,500, reduced by applicable W-2 wages.

Half deduction

The deduction for half of the Social Security and Medicare portion of self-employment tax when figuring income tax. It excludes Additional Medicare tax.