Child Support Calculators: Are They Accurate?

Custodial parents and non-custodial parents alike turn to online child support calculators to try to estimate the child support amount. 

It does not matter if the parents' relationship is intact or has dissolved. Every parent must provide financial support for the child's well-being; this is the legal basis for child support. But one of the most frequently asked questions in any child custody case is, "How much child support will I need to pay?"

Even if you and your co-parent have agreed on a child support payment, the judge's decision for the amount of child support that you pay could be different than what you see on the calculator. Judges base their decision on many factors.

This article provides information on why child support calculators can only provide an approximation of the child support you may owe. You can also use the questionnaire at the bottom of the page to estimate how much child support might cost.

What Is a Child Support Calculator?

Every state offers some way for parents to estimate child support payments. This tool is usually an online calculator that computes child support payments based on the financial information you input. The calculator usually resembles an online worksheet.

A child support calculator will request information such as:

  • Parents' income (each parent's monthly income)
  • The percentage of time the child spends with each parent (parenting time)
  • Any benefits or tax credits you receive

Gathering Information Needed for Child Support Calculators

Before you can calculate the child support amount, you must gather specific information. Income information is a significant starting point. For child support purposes, “income" isn't just your salary and wages. “Gross monthly income" also includes pensions, workers' compensation, and spousal support/alimony. Net income is gross income minus certain expenses. You can subtract federal and state income taxes and taxes for Social Security, for example. You can include the number of children into the calculator.

After entering this information, the child support calculator uses a state-specific formula to predict how much you or the other parent will owe in monthly child support payments.

The Calculator's Result May Not Be Accurate for Your Situation

A child support calculator gives you a ballpark idea of how much your child support payment might be. But it is not, and cannot be, absolutely accurate. The calculator should provide a disclaimer that says it can only provide an estimate.

There are too many factors that a judge considers when arriving at a child support decision. A child support obligation varies drastically from one parent to another.

Factors Not Included in the Calculator

For one thing, you may interpret your financial and living situation differently than a judge would. You may have assumed that your child will spend 25% of their time with you. The judge may order 50% time. That will impact the child support order.

Day care/child care costs, education costs, and medical expenses, including health care and health insurance costs, may be part of the child support calculator, depending on what state you live in. If you have a "special needs" child, you probably have to pay for additional expenses to help your child. These expenses are not factors included in the calculator. A judge, on the other hand, incorporates these into their child support calculation.

Judges follow the state's child support guidelines. The needs of the children are the main focus of the guidelines. These guidelines tend to be highly technical, which is why child support calculators are popular. They simplify complex calculations. The cost of simplification is some inaccuracy.

The guidelines often calculate the child support amount as a percentage of the paying parent's income that increases with the number of children that the parent supports. The parent's time with the child, including overnights, may also be a factor. Sometimes, the family law courts deviate from the guidelines. But the judge can deviate only if they have valid reasons to do so.

Parents Can Agree on a Different Amount

What if you feel that a child support calculator's figure is too low or too high? Can you arrange with the other parent to pay a different amount?

Yes, most states allow parents to negotiate their own child custody plans and child support agreements, as long as they are reasonable. However, the judge can modify that child support agreement if they believe the terms are unfair or not in the best interest of the child. The judge may need to enter findings for deviating from the child support guidelines.

How To Model Your Income and Household Expenses

Having a good idea of your sources of income and monthly expenses will help you and your attorney estimate child support. 

Income includes more than your salary from your paycheck and pay stubs. Alimony or spousal support and unemployment are also included in your income. You should disclose if you receive SSDI or SSI benefits, public assistance benefits, and TANF.

Your expenses can include educational costs, childcare expenses, and daycare. Additional expenses, including medical expenses like health insurance premiums and dental care, will also count.

Use the following form as a guide to help gather the necessary financial information in preparation for the court order.




Gross Monthly Income
  Source/Amount Source/Amount
  _________/$________ _________/$________
  _________/$________ _________/$________
  _________/$________ _________/$________
TOTAL: $________________ $________________
Monthly Deductions from Gross Income
State Income Tax $____________________ $____________________
Federal Income Tax $____________________ $____________________
Social Security $____________________ $____________________
Self-employment Tax $____________________ $____________________
Health Insurance $____________________ $____________________
Union Dues $____________________ $____________________
Pension/Retirement $____________________ $____________________
Mandatory? Yes ____ No ____ Yes ____ No ____
Other Support Orders $____________________ $____________________
Other $____________________ $____________________
TOTAL DEDUCTIONS: $_______________ $_______________

(Gross Income minus Total Deductions)

  $_______________ $_______________
Monthly Expenses:
Rent or Mortgage $_______________ $_______________
Telephone (landline) $_______________ $_______________
Gas $_______________ $_______________
Electricity $_______________ $_______________
Water & Sewer $_______________ $_______________
Garbage Collection $_______________ $_______________
Cable Television $_______________ $_______________
Cellular Phone $_______________ $_______________
Internet Service $_______________ $_______________
Property Taxes $_______________ $_______________
Medical $_______________ $_______________
Dental $_______________ $_______________
Life $_______________ $_______________
Disability $_______________ $_______________
Long-term Care $_______________ $_______________
Homeowners/Renters $_______________ $_______________
Auto(s) $_______________ $_______________
Recreational Vehicle $_______________ $_______________
Debt Payments:
Vehicle #1 $_______________ $_______________
Vehicle #2 $_______________ $_______________
Home Equity Loan $_______________ $_______________
Student Loan $_______________ $_______________
Other Loans $_______________ $_______________
Credit Card #1 $_______________ $_______________
Credit Card #2 $_______________ $_______________
Credit Card #3 $_______________ $_______________
Educational Expenses:
For Self $_______________ $_______________
For Children $_______________ $_______________
Day Care:
For Children $_______________ $_______________
For Parent(s) $_______________ $_______________
Transportation Expenses:
Gasoline $_______________ $_______________
Parking/Commuting $_______________ $_______________
Vehicle Maintenance $_______________ $_______________
Licenses $_______________ $_______________
Groceries $_______________ $_______________
Take-out Food $_______________ $_______________
Restaurants $_______________ $_______________
School Lunches $_______________ $_______________
For Self $_______________ $_______________
For Children $_______________ $_______________
Repair and Cleaning $_______________ $_______________
Household Expenses:
Cleaning Supplies $_______________ $_______________
Cleaning Service $_______________ $_______________
Yard Maintenance $_______________ $_______________
Home Maintenance $_______________ $_______________
Home Security $_______________ $_______________
Home Improvements $_______________ $_______________
Home Furnishings $_______________ $_______________
Appliances $_______________ $_______________
Uninsured Healthcare Costs:
Medical (Self) $_______________ $_______________
Medical (Children) $_______________ $_______________
Dental (Self) $_______________ $_______________
Dental (Children) $_______________ $_______________
Prescript. (Self) $_______________ $_______________
Prescript. (Children) $_______________ $_______________
Non-prescript. (Self) $_______________ $_______________
Non-prescript. (Child.) $_______________ $_______________
Personal Expenses:
Grooming $_______________ $_______________
Entertainment $_______________ $_______________
Travel $_______________ $_______________
Gifts $_______________ $_______________
Hobbies $_______________ $_______________
Babysitting $_______________ $_______________
Pet-care Costs $_______________ $_______________
Donations $_______________ $_______________
Other Expenses $________________ $_______________
  $_______________ $_______________
  $_______________ $_______________
  $_______________ $_______________
TOTAL MONTHLY EXPENSES: $_______________ $_______________


Get Answers to Your Questions About Child Support Calculations From an Attorney

Child support calculators are only a small part of understanding a parent's child support obligation. Rather than relying on child support calculators, consult an experienced family law attorney. A local child support lawyer can give you personalized legal advice.

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Can I Solve This on My Own or Do I Need an Attorney?

  • Some states allow you to set up child support with forms and court processes
  • You may need legal help to set up or modify child support arrangements
  • If there is conflict, an attorney can advise if the other parent’s actions are legal 

Get tailored advice about paying or receiving child support. Many attorneys offer free consultations.

Find a local attorney

Don't Forget About Estate Planning

Once new child support arrangements are in place, it’s an ideal time to create or change your estate planning forms. Take the time to add new beneficiaries to your will and name a guardian for any minor children. Consider creating a financial power of attorney so your agent can pay bills and make sure your children are provided for. A health care directive explains your health care decisions and takes the decision-making burden off your children when they become adults.

Start Planning