For an income bracket of 28% taxable what amount in charitable donations do I need to offset taxes for 2021?

[VolvoGirl]

If you are able to itemize you just get a percentage of your deductions back. Like if you are in the 25% tax bracket for a $100 deduction you will save $25. It isn't added on to your refund. Deductions reduce your income so you get taxed on a lower amount.

And that is just for the amount that puts you over the Standard Deduction.  Now that the Standard Deduction is higher many people will be switching to the Standard Deduction.  And there is a max 10,000 limit (5,000 MFS) of property tax and state taxes "SALT".  And you can only deduct Medical that’s over 7.5% of your AGI.

For 2021 the standard deduction amounts are:

Single 12,550 + 1,700 for 65 and over or blind (14,250)

HOH 18,800 + 1,700 for 65 and over or blind

Joint 25,100 + 1,350 for each 65 and over or blind

Married filing Separate 12,550 + 1,350 for 65 and over or blind

[rjs]

Itemized deductions, such as charitable donations, are subtracted from your income, not from your tax. To completely eliminate all the tax, you would need to add charitable donations equal to your taxable income shown on Form 1040 line 15. That would reduce your taxable income to zero. It doesn't matter what tax bracket you are in.

There are limits to how much you can deduct for certain types of contributions and certain types of organizations. For 2021 you can deduct up to 100% of your Adjusted Gross Income (AGI) for cash donations to ordinary charitable organizations. Since your taxable income is always less than your AGI, you would be able to deduct the full amount of your taxable income, as long as you are making cash donations to ordinary charities. See IRS Publication 526 for all the details on the deduction limits.

If you have credits that are being subtracted from your tax, you don't have to reduce the taxable income to zero in order to reduce the tax to zero. There is no simple formula to calculate the amount of donations you would need. You would have to use trial and error to determine exactly how much you need in donations to eliminate all the tax. You can just enter one large donation and adjust the amount to see how it affects your tax.