Tax Category Tax: calculations, VAT, self-employment tips and more

How to Calculate Weekly Tax Deductions

Paying taxes is a fact of life; everybody has to do it.

Most people have their weekly tax deductions automatically withheld from their paychecks by their employers. However, whether your weekly tax deductions are automatically withheld for you or not, you can calculate your weekly tax deductions yourself so you are prepared for how much is to be deducted from your weekly pay.

Calculate the Social Security tax deducted from your weekly paycheck by multiplying your gross weekly pay (your taxable pay after pretax payments such as insurance premiums or retirement plan payments have been taken out) by 6.2 per cent; if you are self-employed, multiply your weekly earnings by 12.4 per cent.

Calculate the Medicare tax deducted from your weekly paycheck by multiplying your gross weekly pay by 2.9 per cent, whether you are self-employed or not.

Calculate your federal income tax deduction by multiplying the number of allowances you claimed on your W-4 by £45.60. Subtract this amount from your gross weekly pay.

Compare your calculation with the IRS tax withholding percentages table to determine the percentage of your paycheck that is subject to federal income tax withholding. Multiply that percentage by the amount of your weekly paycheck to determine how much money is being withheld from your weekly paycheck for federal income tax.

Calculate any state income tax deduction from your paycheck by multiplying the percentage subject to tax by your gross weekly earnings.


  • Refer to the state income tax rates; each state has its own rates, and some states do not require its residents to pay state income tax.


  • Beware of not setting aside your weekly tax deductions each week if you are self-employed. Self-employed people do not have deductions automatically withheld from their paychecks, so they are responsible for paying all their taxes themselves.

Things Needed

  • Tax rates
  • Calculator