Spousal Support Duration Calculator

General rules: marriages under 5 years → support 25–50% of marriage length. 5–10 years → 50–60%. 10–20 years → 60–80%. 20+ years → indefinite or until retirement (called "permanent" or "long-term"). State variations: California considers marriages 10+ years "long-term" with no preset duration. Florida (post-2023 reform) eliminated permanent alimony entirely. Massachusetts uses statutory formula by length.

Permanent (lifetime) alimony has been eliminated or restricted in most states since 2010. Florida eliminated it in 2023. Massachusetts capped it in 2011. Colorado moved to formula-based duration in 2014. Texas was always restrictive (max 10 years). Some states still allow indefinite alimony for marriages 20+ years (CA, NY, NJ) but it's subject to modification on retirement. Check current state law - alimony reform is ongoing.

Modification triggers: (1) substantial change in either party's income (job loss, retirement, health), (2) cohabitation by recipient (in most states, with a "supportive relationship" living together), (3) recipient's remarriage (automatic termination in most states), (4) payor's retirement at normal age (often automatic reduction or termination). Document changes and file a motion to modify - alimony doesn't adjust automatically.

Child support is calculated by state-specific income shares formulas, lasts until age 18–21 (or college in some states), and is modifiable based on income changes. Alimony has more discretion (judge-determined or formula by length), continues for the agreed term regardless of the recipient's income (until cohabitation/remarriage), and is generally taxable to neither party (post-2018 TCJA). Child support is a child's right; alimony is the spouse's.