Alimony Duration Calculator
Alimony (also called spousal support or spousal maintenance) is a court-ordered payment from one spouse to another following a divorce. The duration and amount depend heavily on how long the marriage lasted, the financial circumstances of each spouse, and the laws of the state where the divorce is filed. This calculator uses common judicial rules of thumb to estimate duration. Marriages under 5 years often result in no alimony or very short terms; medium-length marriages may see alimony for roughly one-third to one-half the marriage length; marriages over 20 years may lead to long-term or indefinite support. All results are estimates only and do not constitute legal advice.
Alimony duration formula
Estimated Duration = Marriage Length * Duration Factor
Duration Factor: 1/3 (short-term), 1/2 (medium-term), 2/3 (long-term)
Monthly Alimony Estimate = (Payer Income - Recipient Income) * 0.40
Total = Monthly Estimate * (Duration in months)
The 40% rule for estimating monthly amount is a rough approximation used in some jurisdictions. Many states use different formulas. For marriages exceeding 20 years, courts in many states may order indefinite alimony. The calculator caps duration at the marriage length for short and medium marriages.
Factors courts consider
- Length of the marriage (the primary driver of duration).
- Each spouse's income, earning capacity, and employability.
- Standard of living established during the marriage.
- Age, physical, and emotional condition of each spouse.
- Contributions to the marriage, including homemaking and child-rearing.
- Whether one spouse interrupted their career to support the other's education or career.
Alimony duration calculator: frequently asked questions
How long does alimony typically last?
Duration depends on the length of the marriage and the state. Many courts use a rule of thumb of one year of alimony for every two to three years of marriage for short to medium-length marriages. Long marriages (over 20 years) may result in indefinite or permanent alimony. These are guidelines, not guarantees.
What types of alimony exist?
Common types include temporary alimony (during divorce proceedings), rehabilitative alimony (until the recipient becomes self-supporting), reimbursement alimony (to compensate for supporting a spouse through education), and permanent alimony (typically for long marriages where one spouse cannot become self-supporting).
What factors affect alimony duration?
Courts consider the length of the marriage, each spouse's income and earning capacity, standard of living during the marriage, age and health of each spouse, contributions to the marriage (including homemaking), and each state's statutory factors.
Does alimony end automatically?
In many states, alimony ends automatically when the recipient remarries or when either party dies. Courts may also modify or terminate alimony if there is a substantial change in circumstances, such as the recipient becoming financially self-sufficient.
Are these estimates legally binding?
No. This calculator produces rough estimates only, based on common rules of thumb. Actual alimony awards are determined by a judge based on the specific facts of each case and applicable state law. Consult a family law attorney for advice specific to your situation.
Official sources
- U.S. Department of Justice, Family Law resources: Elder Justice Initiative.
- Cornell Law School Legal Information Institute: Alimony (Wex).
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.