In Maryland, the starting point – and often, the ending point – for determining which parent pays child support, and how much, is the "Maryland Child Support Guidelines". The Guidelines are a formula in which separating parents, their lawyers, and/or the court can enter certain data, which the Guidelines' calculator then will use to determine an estimate of how much child support a court may order one parent to pay to the other on a monthly basis.
The Maryland Child Support Enforcement Program website link is: www.dhr.state.md.us/csea/worksheet.htm. The first page of this site contains information regarding the Online Child Support Worksheet of the Maryland Department of Human Resources. I encourage you to read this page, and other relevant pages along the left margin of the site, to learn more about the program and how it might relate to you.
The first page of this site advises that there is a rebuttable presumption in Maryland courts that this worksheet's calculation is the correct amount of child support. A "rebuttable presumption" means that the parties may persuade the court to deviate from the Guidelines in certain circumstances. Even so, the Guidelines and their calculation are useful in providing separating parents a fairly accurate idea of what others who use these same Guidelines may conclude.
The first step in using the Calculator is for you to determine whether Worksheet A ("sole custody") or Worksheet B ("shared custody") applies to you. If you click on either worksheet, it will instruct you at some point that, for purposes of this calculator, "shared custody" means that each parent has the children at least 35% of the time. Time in this context is measured by overnights. Thus, if one parent does NOT have the child for at least 128 overnights during the year (35% of 365), the other parent is deemed to have "sole custody" for purposes of this calculation. Be sure to count ALL overnights, including vacations, school breaks, holidays, etc., in which there may be deviations from the usual weekly schedule.
The second step is to go to the appropriate Worksheet and enter the requested data. You will be asked for a court and case name and number – you can make it up because it does not affect the calculation. All calculations will be made by the computer from the data you enter. The worksheet indicates the data you will need, including each parent's gross income (before taxes and other deductions), the number of overnights for each parent (if this hasn't been decided yet, you can estimate), expenses of child care so that the parents can work, health insurance (ONLY for the child or children – for example, if a policy that includes the children is $250 a month, and a policy for the parent only would be $150 a month, the cost of the children's health insurance would be $100 a month), etc.
The calculator may be useful to you to get a ballpark estimate of what each parent's child support responsibility might be. Be aware, however, that I do not and cannot guarantee the accuracy of the calculator, and you should not rely on your use of it in lieu of legal advice from a licensed attorney, which I urge you to seek.