Maryland Rule 9206 contains worksheets the court uses to calculate child support based on primary or shared physical custody. See how parenting time affects the total.To compute child support for split custody, you have to take several steps. You will use the child support guidelines to see what each parent owes the other. To calculate the amount of support under Maryland's current child support guidelines, you can use the official Maryland Child Support Calculator. NOTE: The amount owed in a shared custody arrangement may not exceed the amount that would be owed if the obligor parent were a non-custodial parent. This is the presumed correct amount of child support. The following calculator provides an estimate of a potential alimony award in the State of Maryland. Use this calculator to estimate what you would be obligated to pay. Alimony Calculated In Maryland.