FWIW, I can understand how this can occur. I have a friend in NC who is divorcing after 23 years. There are four children- two in their teens (14,16) and two in elementary school (6,8).

The oldest does not want to stay with both parents, preferring to have one home base. Hard on the parent that is being slighted now- but the teen years are tough- and figuring out which battles to fight- and how to manage the new reality means focusing on what you can control. In this case, ensuring the safety of all, counseling for the older ones, and mediation with the ex-husband.

Good luck to you.

My non legal advice would be to do the calculations twice. Once to determine the support parent 1 would owe for 2 kids, and then determine the amount parent 2 would owe for one child. Then subtract the smaller number from the larger, and you have an approximation. However, you need a lawyer, and you will need to convince a judge that separating the children is a good idea which may be harder than you think.

You might want to post this in th special circumstances concerns forums. It sounds like you will be separating the siblings when you divorce. Why?

I have a question about the situation where each parent is going to be the custodial parent of some of their kids in common.
Say the mother is going to have two of the kids and the father is going to have one of the kids. When using the child support guideline calculator to figure out everyone's support payments, do you list the two kids living with the mother as "additional children living in the home whom she has a legal duty to support" (even if those kids are getting child support from the dad)? And do you list the one child living with the dad as an additional child whom the father has a legal duty support (even if that child is getting child support from the mother)? Or does "additional children" only refer to children not in common with the payor?