Which expenses may be deducted from net income for maaser purposes: e.g. mortgage, real estate taxes, transportation to work etc.?
Only those expenses related to one’s work may be deducted for maaser purposes. The mortgage on a private home, and similar expenses, cannot be deducted, because they are unrelated to one’s work. However, the cost of transportation may be deducted, because this is part of the investment one makes in working — it is a work-related expense — and and it can be deducted to compute one’s “net income.”