DAF Tax Deduction Calculator — 2026

Funding a Donor-Advised Fund creates two federal tax benefits: an income tax deduction (up to 60% of AGI for cash, 30% for appreciated stock) and, for appreciated positions, capital gains tax permanently avoided. The 2026 One Big Beautiful Bill Act adds two adjustments — a 0.5%-of-AGI floor on charitable deductions and a 35% cap on deduction value for 37%-bracket filers. This calculator shows your combined tax benefit, line by line, using verified 2026 values.

How the 2026 OBBBA rules change your DAF deduction

The 0.5%-of-AGI floor

Starting in 2026, the One Big Beautiful Bill Act reduces your otherwise-deductible charitable contributions by 0.5% of AGI. On a $1M AGI that's $5,000 shaved from every year's deduction — modest relative to large gifts, but real at scale. The floor is applied before the 60%/30% AGI ceiling test and before comparing against the standard deduction.

The 35% cap for 37%-bracket filers (MFJ income > $768,700; single > $640,600)

For taxpayers in the top bracket, the OBBBA limits the tax value of itemized deductions to 35 cents per dollar rather than the full 37 cents. Mechanically: a 2/37 reduction applies to the lesser of your total itemized deductions or your income above the 37% threshold. For a $200,000 DAF contribution at a marginal 37% rate, the effective savings rate is 35% — a difference of roughly $3,900. Capital gains avoidance from appreciated stock frequently more than offsets this cap.

Cash vs. appreciated stock: why stock usually wins

Cash and appreciated stock both generate the same income tax deduction (same FMV, same AGI limits). But appreciated stock also permanently eliminates the embedded capital gain — which never gets recognized even if the DAF later sells to grant. A $500,000 stock position with a $50,000 basis and a 15% LTCG + 3.8% NIIT rate carries $85,500 in capital gains liability. Donating it to a DAF wipes that liability at the same time as generating the deduction. By comparison, selling and donating the $500,000 cash would produce the same deduction but you'd pay $85,500 in federal tax first.

AGI limits and the 5-year carryforward

Cash contributions to a public charity DAF: deductible up to 60% of AGI. Appreciated stock: up to 30% of AGI. ² Excess carries forward for five years. Donors near these limits often front-load contributions in high-income years — the year a business sells, a large bonus vests, or a Roth conversion pushes AGI unusually high.

Does bunching help?

If your other itemized deductions hover near the standard deduction ($32,200 MFJ / $16,100 single for 2026), small annual gifts add little income tax value because you'd take the standard deduction anyway. Bunching three to five years of giving into a single DAF contribution in a high-income year solves this: the large deduction clears the standard deduction hurdle, you get a tax benefit in year one, and the DAF distributes to charities on the multi-year schedule you prefer. The charitable bunching calculator on this site models the math.