How Is Alimony Calculated? Duration, Amount, and What Courts Actually Look At

Alimony is the most negotiated and least predictable element of most divorce settlements. There is no federal formula. State law governs, and even within a state, judicial discretion is wide. Here's how courts actually arrive at a number — and why the after-tax modeling matters as much as the formula.

Step one: does alimony apply at all?

Most states require the requesting spouse to meet a threshold showing before the amount-and-duration analysis begins. Typical threshold tests:

• Needs and ability to pay. The recipient must demonstrate financial need beyond what their own resources can cover. The payer must have the ability to pay without reducing their own basic needs.
• Marriage length minimums. Texas, for example, generally requires a marriage of at least 10 years (or proof of family violence) before a court may order spousal maintenance.¹ Shorter marriages in most states get bridge-the-gap or rehabilitative support only in limited circumstances.
• Self-sufficiency standard. In most states, if the requesting spouse can become self-supporting with reasonable effort, permanent support is unavailable — they may get rehabilitative support for a defined period instead.

The four types of spousal support still awarded

Courts don't award a generic "alimony" — they award a specific type, each with different rules around duration and modifiability:

• Temporary (pendente lite). Ordered during the divorce proceedings, before the final decree. Covers living expenses while the case is pending. Ends automatically when the decree is entered — it doesn't bind the final order.
• Rehabilitative. The most common form in modern divorces. Designed to give the lower-earning spouse time to become self-sufficient — finish a degree, re-enter the workforce, complete job training. Duration is tied to a specific rehabilitative plan and typically terminates when that plan concludes or by a fixed end date.
• Durational. A fixed-term award not tied to a rehabilitative plan. Used when the marriage was long enough to justify support but the recipient doesn't need "rehabilitation" — rather, a transition period. Florida restructured most of its awards into this category after eliminating permanent alimony in 2023.²
• Permanent (or open-durational). No fixed end date; continues until a court-ordered termination event (recipient remarries, either party dies, or court-ordered modification). California, New York, and Massachusetts retain judicial discretion to award open-ended support in long marriages where the recipient cannot become self-sufficient. Florida eliminated permanent alimony effective July 1, 2023 for new petitions. Texas has never permitted it except by mutual agreement.¹²

The six factors that drive the amount

No state uses income differential alone. Most follow a multi-factor framework derived from the Uniform Marriage and Divorce Act or their own family code. The factors that matter most in practice:

1. Income and earning capacity of each spouse. The gap between what the payer earns and what the recipient earns (or realistically can earn) is the dominant driver in most discretionary states. Courts look at actual income, imputed income (what the recipient could earn with reasonable effort), and business income for self-employed spouses.
2. Standard of living during the marriage. Support is typically calibrated to maintain something close to the marital standard. Higher-income marriages generate larger awards even at the same income differential.
3. Length of the marriage. The single largest driver of duration. Most states apply rough proportions — see the duration table below. A 3-year marriage rarely generates any long-term award; a 25-year marriage may generate open-ended support.
4. Age and health. A 58-year-old recipient who left the workforce for 20 years to raise children faces different self-sufficiency prospects than a 38-year-old who left for 5 years. Poor health that limits earning capacity can convert a rehabilitative award into a permanent one.
5. Career sacrifices and contributions. Courts credit the spouse who put a career on hold for childcare, supported the other through professional school, or relocated for the other's job. This factor often tips durational awards toward the longer end of the range.
6. Assets and liabilities received in the property settlement. Alimony and property division are evaluated together. A recipient who receives income-generating assets (rental properties, a large investment account) has less support need. The CDFA's job is to model this interaction before the settlement is signed.

Duration guidelines: how marriage length drives the award

While no federal rule mandates this, a practical industry understanding — and statutory guidance in many states — ties duration to a fraction of the marriage length. Common patterns:

These are industry patterns, not statutory mandates. Individual judges vary, and the specific factors above can shift a case significantly in either direction.

States with explicit formulas vs. discretionary states

Most states leave amount entirely to judicial discretion. A handful have adopted income-based formulas, which make the number more predictable — and more negotiable, because both sides can model it in advance.

New York: the DRL § 236 income formula

New York uses a two-formula system under Domestic Relations Law § 236(B)(5-a), and courts apply whichever produces the lower result.³ For cases without child support:

• Formula A: (payer's income × 30%) minus (recipient's income × 20%)
• Formula B: 40% of combined income minus recipient's income

The income cap for 2026 is $241,000. For payer income above that level, the court has discretion to award additional maintenance based on the full statutory factor list. A self-support reserve ($21,546 for 2026) limits how far the payor's income can be reduced.

Duration in New York is also formula-guided: roughly 15%–30% of the marriage length for short marriages, scaling upward to open-ended for marriages of 20+ years.

Texas: statutory caps and explicit duration tiers

Texas is unusual in restricting spousal maintenance to specific situations (family violence, or marriages of 10+ years where the recipient cannot meet minimum reasonable needs). When maintenance is awarded, the amount is capped at the lesser of $5,000 per month or 20% of the payor's average monthly gross income.¹ Duration caps are statutory:

• 10–19 year marriage: maximum 5 years
• 20–29 year marriage: maximum 7 years
• 30+ year marriage: maximum 10 years

Texas Family Code § 8.059 permits contractually agreed-upon spousal support that exceeds these statutory limits — parties can negotiate higher amounts or longer durations as part of a mediated settlement.

Florida: permanent alimony eliminated (effective July 1, 2023)

Florida's CS/HB 1409, signed June 30, 2023, eliminated permanent alimony for all new petitions filed on or after July 1, 2023.² Available types are now: temporary, bridge-the-gap, rehabilitative, and durational. Duration is capped based on marriage length (short-term <7 years, moderate-term 7–17 years, long-term 17+ years), with the maximum durational award limited to half the length of the marriage for short- and moderate-term marriages. Florida also added a presumption against permanent alimony for moderate-term marriages.

California: no formula, but a practical rule of thumb

California has no statutory formula for spousal support amounts. Courts apply Family Code § 4320 factors, with judicial discretion dominating. The widely-cited "rule of thumb" — that support lasts roughly half the length of a marriage under 10 years — is not statutory, but reflects common practice in many California courts. For marriages over 10 years, the court retains jurisdiction indefinitely, and permanent support remains available.

The post-TCJA factor: the gross number isn't the right number

For any divorce finalized after December 31, 2018, alimony is not deductible by the payer and not taxable income to the recipient.⁴ Before the Tax Cuts and Jobs Act, alimony was a deductible/includable transfer — the payer got relief at their (higher) bracket, the recipient reported it at their (lower) bracket, and the net tax burden was reduced for both.

Under post-TCJA rules, $60,000 of alimony costs the payer $60,000 with no deduction. A payer in the 32% bracket who previously received a $19,200 annual tax benefit now gets nothing. That shifts the real cost of the same nominal payment significantly.

What this means in practice: if you're negotiating a post-2018 settlement, the payer needs to think in gross-cost terms, not deductible-cost terms. A $5,000/month award "feels" $5,000 in both scenarios on paper, but the after-tax cost to the payer differs by thousands per year. The right frame for any negotiation is after-tax present value — which is exactly what the alimony present value calculator models.

Common alimony calculation mistakes

• Treating pre-tax dollars as equal to post-tax dollars. A $600,000 retirement account and $600,000 in home equity are not equivalent after-tax assets. Similarly, a $5,000/month alimony award under pre-2019 rules is not economically equivalent to $5,000/month under post-2018 rules.
• Ignoring IRMAA for grey divorces. If you're 55–65 and earned joint income of $200,000+ during the marriage, the divorce-year income spike — especially from lump-sum distributions or asset sales — can trigger Medicare premium surcharges 2 years later. A $400/month IRMAA surcharge effectively increases the real cost of a settlement that triggered it.
• Settling without modeling the interaction with property division. Courts look at alimony and property division together. Taking more illiquid assets (rental property, a business interest) in exchange for lower alimony may seem rational until you model the cash-flow reality of carrying those assets on a single income.
• Overlooking the modification risk. All non-permanent alimony is modifiable on a showing of substantial change in circumstances (either party's income, health, cohabitation). If the award is likely to be modified before the end of its term, the present-value calculation should reflect that probability — not assume the full stream.

Sources

1. Texas Family Code § 8.054 — Duration of Maintenance (Texas Legislature). Sets statutory maximum durations: 5 years (10–19 yr marriage or family violence), 7 years (20–29 yr), 10 years (30+ yr).
2. Florida CS/HB 1409 (2023) — Alimony Reform Bill Summary (Florida Senate). Eliminates permanent alimony; limits awards to temporary, bridge-the-gap, rehabilitative, and durational; effective July 1, 2023 for new petitions.
3. New York Domestic Relations Law § 236(B)(5-a) — Maintenance Guidelines (NY Senate). Income-based spousal support formula; 2026 income cap $241,000; self-support reserve $21,546.
4. IRS Tax Topic 452 — Alimony and Separate Maintenance (IRS.gov). Confirms post-2018 treatment: alimony not deductible by payer, not includable by recipient; pre-2019 divorces grandfathered.
5. IRS Publication 504 — Divorced or Separated Individuals (IRS.gov). Comprehensive IRS guidance on spousal support, filing status, property settlements, and QDROs for divorcing individuals.

State alimony laws change frequently. The information above reflects rules in effect as of May 2026; Texas Family Code § 8.054, Florida Fla. Stat. § 61.08 (as amended 2023), and New York DRL § 236. Consult a licensed family law attorney in your state for current rules. This content does not constitute legal, tax, or financial advice.