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Idaho Alimony Calculator (2026)

Idaho Code § 32-705 makes clear the state has no fixed alimony formula; courts weigh factors such as each spouse’s property, earning capacity and the need for self‑support. Because Idaho only awards maintenance when the requesting spouse lacks sufficient property and cannot be self‑supporting, practitioners often rely on the American Academy of Matrimonial Lawyers rule‑of‑thumb as an estimate—not a legal requirement.

Reviewed 2026-09-02 · Estimates only — not legal or financial advice.

Idaho has no statutory alimony formula. Courts decide case by case under Idaho Code § 32-705. The calculator below shows a widely used rule of thumb (the AAML guideline) as a negotiation starting point — it is not the law and a judge may land anywhere the factors justify.
Before taxes.
Before taxes.
The law behind this calculator: Idaho spousal maintenance factors — Idaho Code § 32-705.

How Idaho calculates it

  • Calculate 30% of the higher‑earning spouse’s gross annual income.
  • Calculate 20% of the lower‑earning spouse’s gross annual income.
  • Subtract the lower‑earner amount from the higher‑earner amount to get a preliminary support figure.
  • Apply the 40% combined‑income cap so the recipient’s total income does not exceed 40% of the couple’s combined income.
  • Estimate duration: if marriage <3 years use 30% of the months, 3–10 years use 50%, 10–20 years use 75%, and marriages over 20 years are considered indefinite.

Worked example

In the example, the higher earner makes $100,000 per year and the lower earner $40,000 per year, with a 12‑year marriage. 30% × $100,000 equals $30,000; 20% × $40,000 equals $8,000; the difference is $22,000 per year, which the 40% cap reduces to $16,000, or about $1,333 per month as a rule‑of‑thumb starting point. For a 12‑year marriage (which falls in the 10–20‑year bracket), the duration guide is 75% of 144 months, roughly 108 months. The court is not bound by any of this.

Frequently asked questions

When can I request spousal maintenance in Idaho?

Under Idaho Code § 32-705 a spouse may seek maintenance only if they lack sufficient property and cannot support themselves, and the court will consider factors like earning capacity, age, and the standard of living during the marriage.

Is alimony taxable in Idaho?

Idaho does not have a separate state tax on alimony; it follows federal treatment. Alimony received is taxable to the recipient and, for divorces finalized before 2019, deductible by the payer; post‑2019 divorces follow the federal rule that eliminates the deduction.

How long might alimony last for a five‑year Idaho marriage?

The rule‑of‑thumb suggests a duration of 50% of the marriage months. Five years equals 60 months, so the estimate is 30 months of support, though the court can set a different period.

Can alimony be reduced if the recipient gets a higher‑paying job?

Idaho courts can modify maintenance if there’s a substantial change in circumstances, such as a significant increase in the recipient’s income, even though the rule‑of‑thumb does not automatically adjust.

What recent changes affect Idaho alimony calculations?

Idaho has not adopted a statutory formula; the AAML guideline remains a widely used estimate. No recent legislative changes have altered the statutory factors, but case law continues to shape how courts apply those factors.

Is the calculation different in Boise, Meridian or Nampa?

No. Idaho Code § 32-705 applies statewide, so courts in Boise, Meridian, Nampa and every other county start from the same guideline. Local practice can differ in how judges weigh deviation factors and in typical negotiated outcomes, but the formula on this page is the one used across Idaho.

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