 All you really have to do is see how much you're spending each month. The total debit line on your statement, on your monthly checking statement, will show you how much money came out of your account. And then this may sound daunting, but if you're already online looking at your statement, look at the next 11 statements. So now you've got 12 total debits, one total debit off of each statement. Add them up, divide by 12, and you'll have a really good idea of