Child support is a payment by one parent to the other for the support of their common child. Usually, the parent who doesn't have custody of the child is required to pay child support. Most states have established formulas that are used to determine the amount of the child support payment which is based on the respective net incomes of the parents, including wages and investments. The formula also considers the amount of time each parent spends with the child, the number of common children the parents have, and special circumstances like travel expenses incurred for child visitation. Child support is tax-free to the parent who receives it, and is not deductible for the parent who pays it. Alimony is an allowance made to one spouse by the other for support during or after legal separation or divorce. It's designed to provide the lower-income spouse with money for living expenses over and above any money that's provided by child support. There are several factors a judge considers when deciding whether to grant alimony. These differ from state to state, but they usually involve factors like the parties' relative ability to earn money, both now and in the future; their respective age and health; the length of the marriage; the kind of property involved; and the conduct of the parties. Alimony is tax deductible to the person who pays it and included in the taxable income of the person who receives it.