The comparison. Every strategy sends the same dollars to charity. For each year we figure your federal and state tax with no giving, then again with each strategy, and the difference is the tax you save. If you give appreciated shares and would have sold them someday, we also count the capital gains tax you never pay. Net cost is what you gave minus all of that.

Itemizing. Each year the tool picks whichever is better for you, the standard deduction or itemizing. Charity only helps as an itemized deduction once your total itemized deductions beat the standard deduction. Non-itemizers get a separate deduction for cash gifts made directly to public charities, up to $1,000 single or $2,000 joint. DAF contributions and stock gifts don't qualify for that one.

2026 rules built in. Itemizers lose the first 0.5% of AGI in charitable gifts. People in the 37% bracket see itemized deductions capped at a 35% benefit. Cash gifts are limited to 60% of AGI and appreciated stock held over a year to 30%, with anything above that carried forward for up to five years. Stock held a year or less is deducted at cost basis. Brackets, the standard deduction and the QCD limit are indexed by the inflation rate you enter. The $1,000 and $2,000 non-itemizer amounts are not indexed.

QCDs. Starting at 70½, an IRA owner can send up to $111,000 (2026) straight to charity. It never shows up in AGI, so you get the full benefit whether or not you itemize. The tool assumes the IRA money would have come out anyway, as an RMD or a planned withdrawal, which is why your income should include it. QCDs can't go to a DAF. The limit is per IRA owner and we use one owner to keep it conservative.

Simplifications. All income is treated as ordinary income. State tax is a flat rate that follows your federal itemizing choice. We don't model AMT, IRMAA, the Social Security tax torpedo, the senior bonus deduction, private foundations, or the fact that some floor amounts can carry forward. Estate tax isn't in the comparison because every strategy moves the same dollars out of your estate.

Sources. 2026 brackets and standard deductions from IRS Rev. Proc. 2025-32. 2026 QCD limit of $111,000 from IRS Notice 2025-67. The non-itemizer deduction, 0.5% AGI floor and 35% cap come from the One Big Beautiful Bill Act (Public Law 119-21), effective for 2026.