# How to Calculate Self Employed Income Tax

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The self-employment tax is the equivalent of the FICA taxes that are imposed on employee income, except the rates appear twice as high. The IRS takes the position that you're both employer and employee when you work for yourself. Normally, your employer would pay half of these taxes and you would pay the other half, but you must pay both the employer and the employee portions if you're self-employed.

You’re responsible for paying not only income taxes on your earnings, but the self-employment tax as well if you have net self-employment income of ​\$400 or more​. Net income is what remains after you subtract your ordinary and necessary business expenses.

## The Contribution and Benefit Base

The self-employment tax is comprised of two taxes: the Social Security tax of ​12.4 percent​ and the Medicare tax of ​2.9 percent​, for a total of ​15.3 percent​. The Medicare portion of the self-employment tax applies to all your self-employment income. But the Social Security portion applies only to self-employment income up to the annual contribution and benefit base for the year. Any self-employment income in excess of the contribution and benefit base is exempt from the Social Security portion of the self-employment tax.

This base is ​\$147,700 in 2022​, up from ​\$142,800 in 2021​ because it's adjusted annually for inflation. You'd use the 2021 figure to calculate the tax you owe on the return you'd file for the 2021 tax year in 2022. You won’t have to pay the Social Security portion of the tax on earned income in excess of \$142,800.

## Self-Employment Tax Formula

You must first calculate your net self-employment income to figure out how much self-employment tax you'll owe. Subtract your deductible business expenses from your gross receipts on Schedule C. You can then calculate your self-employment tax using Schedule SE when you've determined your net self-employment income.

First calculate your self-employment income subject to the self-employment tax by multiplying your total Schedule C income by ​0.9235​ if your earnings don't exceed the contribution and benefit base of \$142,800 for the 2021 tax year. Only ​92.35 percent​ of self-employment earnings are subject to these taxes. Then multiply the result by ​0.124​, the Social Security tax rate. Multiply it by ​0.029​, the Medicare tax rate. Add the two together to arrive at your self-employment tax.

Let's say you had a \$100,000 salaried job in 2021 and your net self-employment income for the year was \$40,000 when the contribution and benefit base was \$142,800. This gives you a total income of \$140,000. You would owe Social Security tax on your entire net self-employment income because \$140,000 doesn't reach the benefit base of \$142,800. Only the portion of your earnings above \$142,800 would be exempt from the Social Security tax for the year.

Now multiply your \$40,000 in net self-employment earnings by 0.9235 to get \$36,940. You can forget your \$100,000 in salary because presumably FICA taxes have already been withheld from those earnings by your employer.

Multiply \$36,940 by 0.124 to find that you’ll owe \$4,580 for the Social Security portion. Next, multiply \$36,940 by 0.029 to find you’ll owe \$1,071 for the Medicare portion. Add \$4,580 and \$1,205 to find your total self-employment tax of \$5,651.

Instructions for the calculation process are clearly outlined, step by step, in IRS Schedule SE.