For divorce agreements finalized on or after January 1, 2019, alimony is no longer deductible by the payer or taxable to the recipient under federal law, due to the Tax Cuts and Jobs Act. Agreements finalized before 2019 generally keep the old tax treatment unless modified.

Alimony / Spousal Support Calculator

Q: How is alimony calculated?

Many practitioners use the AAML guideline as a starting point: 30% of the higher earner's gross income minus 20% of the lower earner's gross income, with the result capped so the recipient does not end up with more than 40% of the couple's combined income. Most states, however, leave the amount to judicial discretion guided by statutory factors rather than a fixed formula.

Q: How long does alimony last?

Duration is usually tied to the length of the marriage. Short marriages may yield only temporary support during the divorce; medium-length marriages often produce rehabilitative alimony lasting 30 to 50 percent of the marriage length; and marriages of 20 years or more can result in long-term or indefinite support.

Q: Can alimony be modified or terminated?

Yes. Many awards can be modified when there is a substantial change in circumstances such as job loss, retirement, or a significant change in income. Alimony also commonly terminates on the recipient's remarriage or, in many states, on cohabitation with a new partner, and typically ends at the death of either spouse.

Estimate monthly alimony and total spousal support using the widely cited AAML formula: 30% of the higher earner's gross income minus 20% of the lower earner's gross income, adjusted for marriage length and alimony type. Awards vary significantly by state — some have statutory formulas, others leave it to judicial discretion — so treat the output as a planning estimate.

Marriage & Income Information

State For reference. Calculator uses the AAML guideline.

Marriage length (years)

Higher earner monthly income ($)

Lower earner monthly income ($)

Marriage length category

Alimony type

Legal Disclaimer: Alimony laws vary dramatically by state. Some states (e.g. Texas, North Carolina) heavily restrict alimony; others (e.g. Massachusetts, Florida) have detailed statutory formulas; many leave amount and duration to the judge's discretion. This calculator uses the AAML guideline as a benchmark only and does not reflect any specific state's rules. Always consult a licensed family law attorney before relying on these estimates.

How This Calculator Works

This tool starts from the widely cited AAML guideline (American Academy of Matrimonial Lawyers): take 30% of the higher earner's gross monthly income and subtract 20% of the lower earner's gross monthly income. The result is then run through a combined-income cap so the recipient never ends up with more than 40% of the couple's total income — a guardrail courts apply to keep awards from overshooting.

That capped figure is adjusted by a marriage-length multiplier (shorter marriages scale the amount down, longer marriages up). Finally, the tool estimates duration from the alimony type you select: temporary support runs a fraction of the divorce timeline, rehabilitative support typically lasts about 40% of the marriage length, and permanent support for marriages of 20+ years is treated as indefinite. Multiplying the monthly amount by the duration gives a rough total.

A Worked Example

Consider a 12-year marriage where the higher earner makes $8,000 per month, the lower earner makes $3,000, and the award is rehabilitative.

Step 1 — AAML base: (30% × $8,000) − (20% × $3,000) = $2,400 − $600 = $1,800.

Step 2 — Combined-income cap: 40% × $11,000 = $4,400; minus the recipient's own $3,000 leaves $1,400 of headroom. The cap ($1,400) is lower than the base ($1,800), so $1,400 controls.

Step 3 — A 12-year marriage is "medium," so the multiplier is 1.0, leaving about $1,400 per month.

Step 4 — Rehabilitative duration is roughly 40% of 12 years ≈ 4.8 years, so the total is about $1,400 × 58 months ≈ $81,000. A judge in your state could reach a very different figure.

What Affects Your Alimony Award

Your state's approach. Texas and North Carolina sharply restrict alimony, Massachusetts and Florida have detailed statutes, and many states leave amount and duration almost entirely to the judge.
Length of the marriage. The single biggest driver of duration — long marriages are far more likely to produce long-term or indefinite support.
Income gap and earning capacity. Awards grow with the disparity between spouses and shrink as the lower earner's ability to become self-supporting increases.
Standard of living during the marriage. Courts try to let both spouses approximate the marital lifestyle, which can push awards above a bare formula.
Age, health, and non-financial contributions. A spouse who left the workforce to raise children or who has health limitations may receive more.
Remarriage and cohabitation. Many awards terminate on the recipient's remarriage or cohabitation and end at either spouse's death.

Frequently Asked Questions

How is alimony calculated?

Many practitioners start from the AAML guideline — 30% of the higher earner's gross income minus 20% of the lower earner's — capped so the recipient does not exceed 40% of combined income. Most states, though, leave the amount to judicial discretion guided by statutory factors rather than a fixed formula.

How long does alimony last?

Duration is usually tied to marriage length. Short marriages may yield only temporary support; medium-length marriages often produce rehabilitative alimony lasting 30 to 50 percent of the marriage length; and marriages of 20 years or more can result in long-term or indefinite support.

Is alimony taxable?

For divorce agreements finalized on or after January 1, 2019, alimony is no longer deductible by the payer or taxable to the recipient under federal law, following the Tax Cuts and Jobs Act. Agreements finalized before 2019 generally keep the old tax treatment unless modified.

Can alimony be modified or terminated?

Yes. Many awards can be modified after a substantial change in circumstances such as job loss, retirement, or a major income change. Alimony also commonly terminates on the recipient's remarriage or cohabitation and typically ends at the death of either spouse.

How Alimony Is Determined

Courts typically consider: each spouse's income and earning capacity, marriage length, standard of living during the marriage, age and health of both spouses, contributions to the marriage (including homemaking), and the recipient's ability to become self-supporting. The AAML formula — 30% of the payor's gross income minus 20% of the recipient's — produces an estimate, but the result is generally capped so the recipient does not receive more than 40% of the couple's combined income.

Duration is usually tied to marriage length. Short marriages may yield only temporary support; medium-length marriages often warrant rehabilitative alimony of 30–50% of the marriage length; long marriages may produce long-term or indefinite awards, especially when the recipient cannot reasonably re-enter the workforce.