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Family Law Tool

Spousal Support Calculator

Estimate monthly spousal support — and how long it may last — based on each spouse's income and the length of your marriage.

Estimate your spousal support

Enter a few details for an instant estimate. Nothing is stored.

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How spousal support is estimated

Spousal support (sometimes called alimony or maintenance) is money one spouse pays the other after a separation to help offset a large gap in income. The goal is usually to give the lower-earning spouse time and resources to adjust to life after the marriage.

Two questions drive almost every spousal support discussion:

1. How much?

Many places start from the difference between the two incomes and apply a percentage of that gap. This tool uses roughly 30% of the monthly income difference as a starting point — a common rule-of-thumb — but the real figure can be higher or lower depending on your jurisdiction and needs.

2. For how long?

Duration usually tracks the length of the marriage. Short marriages tend to produce short awards (or none at all), medium-length marriages often produce support for a portion of the years married, and very long marriages can lead to long-term or open-ended support.

Frequently asked questions

It's a general ballpark only. Some states use a formula, others give judges broad discretion, and many cap the amount or duration. For a precise figure based on where you live, speak with a family-law attorney.

Usually it affects duration more than the monthly amount. Longer marriages tend to produce longer support periods, and very long marriages can sometimes lead to indefinite support, depending on your jurisdiction.

Often yes. Many awards can be modified if there's a significant change — a job loss, a big raise, retirement, or remarriage. The rules for modifying support vary by where you live.

Most analyses use gross monthly income from nearly all sources — wages, bonuses, commissions, and self-employment profit. Use a realistic monthly average for each spouse for the best estimate.

This calculator provides a general, simplified estimate for educational purposes only. It is not legal advice and does not reflect any specific jurisdiction's spousal support rules. No attorney-client relationship is formed by using this tool.

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