To start your case, go to a Family Court clerk and ask them to help you with a "Spousal Support Petition. It is recommended to consult with an experienced New York alimony lawyer when petitioning for maintenance in order to avoid any potential mistakes.Worksheets to calculate guideline amounts of maintenance and child support. Optional tools to help with calculations are below. 15.3 of the Divorce Act and the equivalent provincial law provisions. This calculator provides an estimate for a single source of income. Does Texas Have an Alimony Calculator? Like spousal support, child support is based on the relative income of the couple. The amount of child support you pay or receive for children of your relationship. If you have a prenuptial or postnuptial agreement that outlines spousal support in the case of a divorce, the court will generally honor it.