How do you determine the amount per child for deviations to support?

Unlike the support worksheets and the Economic Table, no formula has been adopted as law in Washington state. The Northwest Justice Project prepared a good basic synopsis of child support: “Understanding the Washington State Child Support Schedule and How Child Support Is Set In Washington”, which is available online here: http://www.washingtonlawhelp.org/documents/1480213816EN.pdf?stateabbrev=/WA/ Pages 7-8 specifically deal with deviations from the standard calculation, including paying support for other children. The statute allowing the deviation is here: http://apps.leg.wa.gov/RCW/default.aspx?cite=26.19.075 Whether a judge grants a deviation, and the amount of the deviation, are both discretionary. There were two primary attempts to come up with a formula to calculate support when support is paid for other children: the Blended Family method and the Whole Family approach. Discussion of the two (and others) can be found in the Washington State Child Support Schedule Commission’s Dec. 1989 “Report on Use of Support Schedule for Blended Families”, found here: http://www.legalplus.com/HelpWebHelp/wawin/blended_family_case.htm There is also a study by a Colorado group on 1/20/05, titled "Washington State Child Support Schedule: Selected Issues Affecting Predictability and Adequacy" : http://www.dshs.wa.gov/pdf/esa/dcs/reports/AppendixIV-d.pdf See especially Chapter 3. In Dec. 2008, the Child Support Schedule Workgroup submitted its “Recommendations to the Washington State Legislature for Washington’s Child Support Schedule Pursuant to 2SHB 1009.” It can be viewed here: http://www.dshs.wa.gov/pdf/esa/dcs/finalreportofworkgroup.pdf See especially pages 16-19. However, a review of the Legislature’s changes to the child support schedule and statutes effective October 10/1/09 discloses no adoption of any specific formula for calculating the amount of a deviation for other children. It remains discretionary, based on all the circumstances of the households. These reports may be helpful in presenting your arguments to the judge, who has the ultimate decision.