Generally speaking, child support in most states is calculated on a formula that is adopted by the state legislature and applied by the courts.  This is true in the state of Florida as well.  The court - or the attorneys - have child support worksheets that are standard and they merely plug in numbers to calculate the percentages applicable to each parent.  Joint custody - or 50/50  as you are calling it - does not necessarily mean paying support 50/50. It means that you have joint rights to your daughter and an equal right to make decisions that effect her.  Physical custody is another story and that is a factor in support as well.  Get some legal help inn your area.  Good luck.