The Ohio Child Support Calculator will provide an estimate of the support obligations that may be included in a court or administrative child support order. If you are preparing for a divorce, here is a brief overview of the laws that apply to calculating child support and spousal support in Ohio.Learn How to Calculate Child Support and Other Divorce-Related Payments in Ohio. Planning for your child's financial future. Spousal support and child support are the answer, and we're going to share what you need to know about these two types of support in Ohio. If you have any questions or concerns please feel free to contact us at 513-946-9000. Complete the paperwork. Use the statewide forms to modify a child support order. Do the courts decide how much child support and alimony he will pay even if we agree on a set amount in the dissolution papers? Also; do we have to fill out an affidavit of income if neither party is formally seeking child or spousal support?