Net compensation to Americans in 2012 came to $6.529 trillion according to Social Security, here.
The Giving USA Foundation estimates total charitable giving to all recipients in 2012 at $316 billion, here.
That works out to a rate of giving at 4.8% of what is basically W-2 income, in other words, 4.8% of wages. Not included in that income however would be all sorts of other income, including capital gains income, so the percentage given is considerably lower than 4.8%.
The federal government's Bureau of Economic Analysis in its latest report here puts personal income of the country at $13.743 trillion in 2012. So $316 billion represents just 2.3% of that.
Lest you think that all $316 billion went to church, think again. Just $102 billion went to religious organizations in 2012, or a measly 0.7% of the country's personal income.
75% of the country claims Protestant and Catholic faith. You know, faith in the guy who said "So you cannot become my disciple without giving up everything you own" (Luke 14:33).
Uh huh.