About Coparent Math

An estimate of the guideline amount for a family's real numbers: both incomes, the number of children, days with each parent, child care, health insurance, spousal support and union dues, where the state's formula uses them.

The calculation follows each state's statute step by step and shows its working: the formula, the schedule row, the income shares and the low-income rules, with links to the law and the date each figure applies. The tax figures reproduce the official Texas tax charts to the cent; here is how that is checked.

It covers Virginia, Texas and New York today, one state for each of the main guideline models. All 50 states and DC is the goal.

It is meant for parents who want to understand the number before mediation, a court date or a modification request, or simply to plan a budget: what the number is, why it is that number, and what could change it.

It is not legal advice. A court can order a different amount than the guideline, and an existing order only changes when it is modified. Check a figure with a family law attorney, a mediator, or your state's child support agency before you rely on it.

It is not on either side. The calculator speaks of the parent the children live with and the other parent, draws both parents in the same color, and says who pays from the formula's own result. In Virginia's shared custody formula that can be either parent.

It does not hide its limits. Figures we could not confirm are marked wherever they are used, and the parts of each guideline the engine does not compute yet are listed in how child support is calculated. The calculator keeps nothing you type: see privacy.

Coparent Math is published by Hatim Rih, a software developer.

How it is made. Each state's guideline is written as a rule file: the steps of the formula, the schedule and the dated figures, each with the statute section or official chart it comes from and the date that source was checked. A rules engine runs those files. Every amount on the site, in the calculators and in the guides, is computed by that engine, and the calculator in your browser runs the same engine.

How to get in touch. Use the contact form, or write to contact@coparentmath.com.

How errors are corrected. If a figure looks wrong, report it with the page it is on. It is checked against the source the page cites. A wrong figure is corrected in the rule file or the guide it comes from, so every page that uses it changes together.