what percentage of child support is paid when there is joint custody but shared parenting of one 4 year old child

Hello, Anonymous. The idea behind child support is to reimburse one parent who would otherwise bear a greater financial burden. This is usually figured when one child lives primarily with one parent and has visitation with the other. The parent who is the primary residential parent will usually bear more financial hardships than the non-residential parent. So when the child lives with both parents roughly equally, the financial responsibilities will usually be seen to be split equally already. And more often than not in these situations, child support will be reserved and neither parent will pay the other because they are already equally splitting the costs. If you were to push for primary residential custody, the the financial burden would be shifting against you, and the court would expect the father to help you out financially with child support.  Child support, however, is seen as being paid to the child, not to the parent. The parent is merely the one who is managing the money for the child. So it is not the parent who can waive child support or use it as a bargaining chip. Realistically, to change the arrangement you have right now will be difficult, but it can be done. Your best bet is to hire an attorney in your area who can help you out and try to show the court that the best interests of the child are to live with you primarily and not to go back forth every week. I hope this helps.