Calculating Debt Payoff. If you have unpaid child support debt, you can figure out how long it will take to pay it off with our Arrears Payoff Calculator.The Payment Estimator applies the statewide uniform guideline calculation to the information that you enter into the blank fields. See how parenting time affects the total. Complete the fields below and press calculate to estimate alimony. The figures presented are based on legal California alimony guidelines. This comprehensive guide aims to demystify spousal support, providing you with the necessary insights to handle this sensitive aspect of family law. This article will provide an indepth explanation of how alimony is calculated in California. We will cover the different types of spousal support. Free, online, accurate California divorce child support calculator that estimates county specific payments in Riverside County, California.