Alimony Calculator
Estimate monthly spousal support payments using both spouses' annual incomes, the type of alimony, and any existing child support obligations. Useful during divorce negotiations or financial planning.
About this calculator
Alimony (spousal support) compensates for the income gap created when a marriage ends, helping the lower-earning spouse maintain a reasonable standard of living. The core principle is to take a fraction of the income disparity between the higher and lower earner, convert it to a monthly figure, and subtract any child support already being paid to avoid double-counting. The alimonyType multiplier encodes the percentage of the income gap that applies under different award types — for example, 0.30 for rehabilitative support or 0.40 for long-term support. The formula is: monthlyAlimony = max(0, ((payorIncome − payeeIncome) × alimonyType / 12) − childSupport). The floor of zero ensures the result is never negative. Actual court awards vary substantially by state law, marriage length, and the standard of living established during the marriage.
How to use
Suppose the higher earner makes $96,000/year, the lower earner makes $36,000/year, the alimonyType multiplier is 0.30 (rehabilitative), and existing child support is $500/month. Income gap: $96,000 − $36,000 = $60,000. Annual alimony base: $60,000 × 0.30 = $18,000. Monthly base: $18,000 / 12 = $1,500. Subtract child support: $1,500 − $500 = $1,000/month estimated alimony. Since the result is positive, max(0, …) returns $1,000.
Frequently asked questions
How does the length of marriage affect alimony duration and amount?
Marriage length is one of the most influential factors in alimony determinations. Short marriages (under 5 years) typically result in little or no alimony, or only brief rehabilitative support to help the lower earner regain financial independence. Marriages of 10–20 years often produce time-limited awards lasting a fraction of the marriage's duration. Marriages exceeding 20 years, especially where one spouse left the workforce to raise children, can generate open-ended or permanent support awards. While this calculator focuses on the monthly amount, courts also weigh length heavily when setting the duration of payments.
What is the difference between rehabilitative and permanent alimony?
Rehabilitative alimony is designed to be temporary, giving the recipient time to complete education, job training, or reentry into the workforce. Courts typically set a fixed end date or a milestone — such as completing a degree — at which payments stop. Permanent alimony, now disfavored in many states, continues indefinitely until the recipient remarries or either party dies. Other types include reimbursement alimony (repaying a spouse who supported the other's education) and lump-sum alimony (a single payment instead of ongoing obligations). The alimonyType multiplier in this calculator reflects how aggressively different award types capture the income gap.
Can alimony be modified after a divorce decree is finalized?
Yes, most alimony orders can be modified if there is a substantial change in circumstances. Common triggers include a significant increase or decrease in either party's income, the recipient spouse remarrying or cohabitating with a partner, serious illness, or retirement. The party seeking modification must petition the court and demonstrate the changed circumstances; courts do not modify awards automatically. Some divorce agreements include non-modification clauses that permanently lock the amount and duration, so it is essential to understand what your decree says before assuming you can revisit the terms later.