Alimony Duration Calculator

This calculator estimates how long spousal support might last from the length of the marriage, and totals the payments from the monthly amount you enter; it does not ask for incomes or a state. Having a rough timeframe in hand matters during divorce, since both parties need to anticipate future obligations and resources before they sit down to negotiate. Treat the number here as a starting point for those conversations, not a verdict.

The duration is a rule of thumb, not any one state's statute: about a third of the marriage for marriages under 10 years, half for 10 to 19 years (both rounded to whole years), and potentially indefinite support at 20 years or more. The total is the monthly amount times the months in that duration; at 20 years or more the calculator still totals half the marriage length even though it labels the duration indefinite. State rules differ. In California, half the length of the marriage is generally a reasonable period for the supported spouse to become self-supporting, but a marriage of 10 years or more is presumed to be of long duration and the court keeps jurisdiction over support indefinitely (Family Code §§4320(l), 4336). Florida no longer awards permanent alimony: for cases pending or filed on or after July 1, 2023, durational alimony may not exceed 50% of the length of a marriage under 10 years, 60% of one lasting 10 to 20 years, or 75% of one lasting 20 years or more (Fla. Stat. §61.08).

Whatever figure you see, a judge has the final say, weighing need, ability to pay, and the lifestyle the couple built during the marriage. One frequent misunderstanding is treating the 50% benchmark as automatic, which ignores heavier factors like each spouse's earning capacity and health. Because so much turns on those specifics, this tool is educational only and no substitute for a family law attorney licensed in your state.