What is the test for a judge to determine child support?

It is well established that the amount of child support to be awarded rests in the sound discretion of the trial court. (In re Marriage of Wittgrove (2004) 120 Cal.App.4th 1317, 1327; County of Lake v. Antoni (1993) 18 Cal.App.4th 1102, 1105.) "We cannot substitute our judgment for that of the trial court, but only determine if any judge reasonably could have made such an order. [Citation.] Our review of factual findings is limited to a determination of whether there is any substantial evidence to support the trial court's conclusions." (In re Marriage of Chandler (1997) 60 Cal.App.4th 124, 128.)⁵