Alimony Calculator

Disclaimer: This uses a generic, illustrative formula. Actual alimony varies enormously by jurisdiction and court discretion. Not legal advice.

Illustrating the Mechanics Behind an Income-Gap Formula

Spousal support calculations, where states use a formula at all, generally work from the gap between two spouses' incomes and the length of the marriage. Many states that do provide guideline formulas leave the final figure to judicial discretion rather than a binding number. This calculator applies a simplified, commonly-referenced version of that income-gap approach purely to show how the two variables interact — not to replicate any specific state's actual statute.

Note: This is a generic, illustrative formula only. Actual alimony or spousal support varies enormously by jurisdiction and is ultimately subject to court discretion. This is not legal advice.

The Formula

Annual Alimony = (30% × Payor Income) − (20% × Recipient Income)
Estimated Duration = Marriage Length × Duration Factor

The duration factor scales with how long the marriage lasted, on the illustrative assumption that longer marriages tend toward longer or more extended support:

Illustrative duration factor by marriage length
Marriage lengthDuration factor
Under 5 years0.3
5 to under 10 years0.4
10 to under 20 years0.5
20 years or more0.6

Where This Matters

  • Framing settlement negotiations — a rough figure gives both parties a starting reference point before formal negotiation or mediation.
  • Understanding the income-gap logic — the formula illustrates why alimony scales with the disparity between incomes, not either income alone, since a large gap between two high earners can produce a different result than the same gap between two modest earners.
  • Preparing for a consultation — a preliminary number helps frame realistic questions before meeting with a family law attorney who can apply your state's actual guidelines.

How to Use This Calculator

  1. Enter the paying spouse's annual income.
  2. Enter the receiving spouse's annual income.
  3. Enter the length of the marriage in years.
  4. Select Calculate for an illustrative monthly alimony estimate and duration.

Related Calculations

Also working out child support? See the Child Support Calculator, or check the Legal Fee Calculator for representation costs.