Catholics often ask about tithing…
Although the Church teaches that offering some form of material support to the Church is obligatory for all Catholic adults who are able to do so, it doesn’t specify what percent of one’s income should be given. Remember, tithing was an Old Testament obligation that was incumbent on the Jews under the Law of Moses. Christians are dispensed from the obligation of tithing ten percent of their incomes, but not from the obligation to help the Church.
The key to understanding how God wants us to give to the Church is found in 1 Corinthians 16:2, “On the first day of the week [Sunday] each of you should set aside whatever he can afford,” and in 2 Corinthians 9:5-8,
courtesy of www.catholicssay.com