How do I estimate tax liability for my personal tax extension - form 4868

You only need to estimate your tax liability if you plan to make a payment to the IRS with your tax extension. 

To estimate your tax liability for a personal tax extension, you will need to calculate your total tax liability for the year and subtract any payments or credits that you have already made. Below are the steps to follow:

1. Gather all of your income statements, including W-2 forms, 1099 forms, and any other income documents. Total up all of your income for the year.

2. Determine your deductions. If you are taking the standard deduction, you can simply use the amount for your filing status. If you are itemizing your deductions, you will need to add up all of your deductible expenses, such as mortgage interest, property taxes, state and local income taxes, and charitable contributions.

3. Subtract your deductions from your income to determine your adjusted gross income (AGI).

4. Calculate your tax liability by using the tax tables or tax rates for your filing status and AGI. You can find the tax tables in the instructions for Form 1040.

5. Subtract any credits or payments that you have already made for the year, such as withholdings from your paycheck, estimated tax payments, and any tax credits for which you are eligible.

6. The result is your estimated tax liability for the year.

Once you have estimated your tax liability, you can use this information to determine how much you need to pay with your extension request. 

Note: An extension of time to file does not extend the deadline for paying any taxes owed, so you should still estimate and pay your taxes by the original due date to avoid any penalties or interest. If you do not pay enough with your extension request, you may be subject to penalties and interest on the amount owed.