There are limits to how much you can deduct, but they're very high. For most people, the limits on charitable contributions don't apply. Only if you contribute more than 20% of your adjusted gross income to charity is it necessary to be concerned about donation limits.
https://www.charitynavigator.org/index.cfm?bay=content.view&cpid=31
To figure out how much taxes you have to pay, you have to look at the income tax rate table. For 2011, it looks like this for single people (there’s a different table for married couples): For income between $0 and $8,500, you pay 10% in taxes. For income between $8,500 and $34,500, you pay 15% in taxes.
http://www.thesimpledollar.com/charity-and-your-tax-bill/
How a gift is used affects donor value. For property worth more than $5,000 ($10,000 for stock in closely-held firms), you'll need to get a formal appraisal. Not only that, but you'll have to make sure the appraiser is a member of a recognized professional group or meets minimum education and experience guidelines.
https://turbotax.intuit.com/tax-tools/tax-tips/Tax-Deductions-and-Credits/Charitable-Contributions/INF12011.html
In other words, this person’s $9,000 charitable contribution saved them $2,250 on their taxes. That’s because the person was in the 25% tax bracket before the donation and in the 25% tax bracket after the donation, which means that they essentially saved 25% of their donation on their taxes.
http://www.thesimpledollar.com/charity-and-your-tax-bill/
Where Does Clinton Foundation Money Go? Republican presidential candidate Carly Fiorina says that “so little” of the charitable donations to the Clinton Foundation “actually go to charitable works” — a figure CARLY for America later put at about 6 percent of its annual revenues — but Fiorina is simply wrong.
http://www.factcheck.org/2015/06/where-does-clinton-foundation-money-go/
St. Jude is leading the way the world understands, treats and defeats childhood cancer and other life-threatening diseases.
https://www.stjude.org/about-st-jude/faq.html
So, charitable donations are a great thing and they do offer some tax savings, but you don’t save $1 for every dollar you donate. Instead, you often reduce your tax bill roughly a quarter or so for every dollar you donate. That’s still a great little bonus.
http://www.thesimpledollar.com/charity-and-your-tax-bill/
If the gifts are deductible, the actual cost of the donation is reduced by your tax savings. For example, if you are in the 33% tax bracket, the actual cost of a $100 donation is only $67 ($100 less the $33 tax savings). As your income tax bracket increases, the real cost of your charitable gift decreases, making contributions more attractive for those in higher brackets. The actual cost to a person in the lowest bracket, 15%, for a $100 contribution is $85. For a person in the highest bracket, 35%, the actual cost is only $65.
https://www.charitynavigator.org/index.cfm?bay=content.view&cpid=31
If the claimed value of your donated vehicle is more than $500, in most cases your deduction is limited to the amount the car brings when it's sold at auction. The charity has 30 days after it sells your vehicle to issue you a Form 1098-C that shows the sale price.
https://turbotax.intuit.com/tax-tools/tax-tips/Tax-Deductions-and-Credits/Charitable-Contributions/INF12011.html
Donations are limited. There's also a limit on how much you can deduct. The basic rule is that your contributions to public charities, colleges and religious groups can't exceed 50 percent of your Adjusted Gross Income (AGI). The caps are a bit lower for gifts to other types of nonprofits.
https://turbotax.intuit.com/tax-tools/tax-tips/Tax-Deductions-and-Credits/Charitable-Contributions/INF12011.html
charitable donations - how much do they actually get
From charitable donations, they actually get 15%, for a $100 contribution is $85 for a person with the lowest bracket and 35% that is $65 for the highest bracket. In charitable donations, a person in the lowest bracket gets 15 percent from a $100 contribution which is $85, and for a person in the highest bracket a person gets 35 percent from a $100 which is $65.