There are statutory guidelines defining percentages of gross income (less specified deductions) that is to be paid by the non (physical) custodial spouse with respect to the care of the children.  The other is deemed to be contributing to the children by providing a home. The percentages vary, in NY  from 18% (one child) to 33% (five or more children) on the first combined  $141000, and with higher amounts on a court dictated semi discretionary formula There is also a formula for defined add ons which each spouse must contribute to. In most cases the contributions are approximately in proportion to their relative income, but outliers exist. Calculators abound online.

This can be rigid. It is possible in mediation to arrive at a different formula if one can show reason. This allows a much more flexible approach. However one cannot bypass the children, as the court must approve the arrangement and feel that it was fairly in their interest.

^{THIS INFORMATION IS OF GENERAL NATURE ONLY AND NOT TO BE RELIED UPON IN ANY SPECIFIC SITUATION. IN ALL CASES CONSULT AN ATTORNEY FOR PROPER ADVICE}