FINANCIAL · ALIMONY
Alimony Calculator
Estimate monthly spousal support using the income gap model — enter both spouses' gross incomes and marriage length to get a ballpark alimony estimate. Educational purposes only; consult a family law attorney.
About This Calculator
Get a rough estimate of monthly alimony using the income gap model — a common rule-of-thumb that applies 40% of the monthly income difference between spouses. Enter both gross monthly incomes and the length of the marriage to see an estimated payment amount and duration range. Important: alimony (spousal support) is determined by a judge applying your state's laws, not a single formula. This estimate is educational only.
How It Works
The calculator takes the gross monthly income gap (higher-earning spouse minus lower-earning spouse) and multiplies by 40% — the income gap factor used as a rough starting point in many mediation and planning contexts. The estimated duration depends on the marriage length bucket: short (< 5 years) → about 40% of marriage length; medium (5–9 years) → 50%; long (10–19 years) → 65%; very long (20+ years) → potentially indefinite.
The Formula
Monthly Alimony ≈ (Payor Income − Recipient Income) × 40%
- Payor Income
- Higher-earning spouse's gross monthly income
- Recipient Income
- Lower-earning spouse's gross monthly income
- 40%
- Income gap factor (common rule-of-thumb starting point)
Frequently Asked Questions
- Is this calculator accurate for my state?
- No single formula applies in the US. Every state has its own alimony statute, and courts consider many factors beyond income — standard of living, duration of marriage, age and health of each spouse, contributions to the marriage (including homemaker/childcare roles), future earning capacity, and more. California, Texas, New York, and Florida all use different approaches. This calculator is a planning tool only. Consult a family law attorney in your state.
- What is the income gap model?
- The income gap model is a rule-of-thumb approach used in mediation and planning contexts. It estimates alimony as a percentage (typically 40%) of the difference between the spouses' monthly incomes. Many attorneys use this as a starting-point conversation for settlement negotiations, but courts are not bound by it.
- Does the length of marriage affect alimony?
- Yes, significantly. Short marriages (under 5 years) typically result in shorter-term or no alimony, while long marriages (20+ years) may result in indefinite or permanent support. This calculator models duration as a fraction of the marriage length depending on the marriage length category.
- Can alimony be waived or modified?
- Yes. Alimony may be waived in a prenuptial or postnuptial agreement. It may also be modified if a "substantial change in circumstances" occurs — such as job loss, remarriage, or a significant income change — depending on state law and whether the original order was "modifiable."
- Is alimony tax-deductible?
- For divorces finalized on or after January 1, 2019 (under the Tax Cuts and Jobs Act), alimony is no longer deductible by the payor or includable as income by the recipient. For divorces finalized before 2019, the pre-TCJA tax treatment may still apply.