Here is some information from Charity Navigator to assist you in reviewing your personal finances to determine how much you can afford to give.
“Once you've honed in on your charitable interests, you'll need to review your personal finances and set some giving goals. In general, it is estimated that average annual giving is 3.2% of income. Apply this percentage to your annual income and see if you are comfortable with that level of giving. Even better, break it down per pay period so you'll know exactly how much will be deducted from each paycheck. You might be surprised to find out you can afford to give more than you thought.
After you've calculated how much to contribute, you'll need to remember a few rules in order to maximize the tax benefits of your gift. Payroll deduction is convenient in that you do not need an acknowledgement from the charity to claim your tax deduction. There is however one exception to this rule. If you contribute $250 or more from a single paycheck, then you must prove to the IRS that you (a) made the donation and (b) you didn't receive anything in return for that donation. Simply keeping a copy of your pay stub fulfills the first requirement. To comply with the second, you'll need a pledge card or other documentation from the charity specifically stating that you did not receive any goods or services in return for your gift. If you need some help to determine the level of giving right for you based on the tax benefits of giving, access Charity Navigator's giving calculator.
