The LDS Church teaches that it is ten percent of one's annual income, with it left to the member to determine how to calculate it (e.g., what constitutes "income" and whether it is ten percent of income after or before tax).
The Church of Jesus Christ of Latter-day Saints (LDS) recommends a 10% tithe, leaving it to members to decide how to calculate it (e.g., what constitutes "income" and whether it is 10% of income after or before taxes).