How do I calculate the amount of Social Security tax to withhold for 2025?

Social Security income may be partially taxable depending on your filing status and the level of your combined income, including Social Security income.

To determine how much tax must be withheld for your Social benefits, you need to know how much of those benefits will be taxable.

The IRS has a calculator which you can use to determine how much of your SS benefits is taxable.

You can then add that taxable portion to your other income to calculate your taxable income and your tax liability. The tax to be withheld from your SS benefits would then depend on what is already withheld from your other income.

The total tax withheld should cover at least 90% of your current year's tax liability, or 100% of your prior year's tax liability (110% if your income is above $75,000 (Single) or $150.000 (MFJ).