Calculate alimony quickly and accurately with our state-specific alimony calculators. Get an estimate based on your state's guidelines for free.This calculator is intended to be used only as a general tool to estimate potential splits and payments. Free Florida alimony calculator to estimate annual alimony payments and monthly alimony payments. Here's an alimony calculator that will help you get an idea of the payments and duration. Illinois has established a specific formula for calculating the amount and duration of spousal maintenance obligations or awards. Learn about the types of alimony available in Florida and how judges decide which type to award, how much the payments should be, and how long they'll last. You only have to be in Illinois for 90 days to get a divorce in Illinois. That's not 90 days before filing, that's 90 days before the actual divorce. The Central Depository Child Support and Alimony Office maintains a local Central Depository to receive and process court-ordered payments.