A few states calculate spousal support with an exact statutory formula; most leave it to judicial discretion. Pick your state — formula states use the real formula, discretionary states use the estimation guideline attorneys use.
Illinois, New York, and Colorado (advisory) set maintenance with published formulas based on the spouses' incomes; Texas caps support at a statutory maximum. In the remaining states, judges weigh factors — marriage length, incomes, earning capacity, age, health, and contributions — with no fixed math. For those states our calculator applies the American Academy of Matrimonial Lawyers (AAML) guideline: 30% of the payer's gross income minus 20% of the recipient's, capped at 40% of combined income. It's the ballpark many attorneys and mediators start from.
Every state page notes recent reforms (like Florida's 2023 elimination of permanent alimony), the types of support available, and how duration is typically set.