Charitable Gift Annuity Calculator Charitable Gift Annuity Calculator You can make a gift to Webb Institute and receive guaranteed fixed payments for life. Payments may be much higher than your return on securities or CDs. Gift Amount ($) Property Type Cash Property or stock held for at least 1 year Cost Basis ($) Tax Bracket 10% 12% 22% 24% 32% 35% 37% First Beneficiary Age Second Beneficiary Age Calculate