How to calculate a child support worksheet yourself before filing

Last updated 2026-07-11

Why should you calculate child support before you file?

Running the numbers before you file does two things. It tells you whether the amount you and your spouse agreed on will survive a judge's review, because a court has to approve any child support figure even in an uncontested divorce and can reject one that strays too far from the guideline. It also spares you a bad moment at your hearing when the clerk hands you a blank worksheet and expects it filled out on the spot.

Most states require a completed child support worksheet attached to your divorce paperwork. In Texas, the Office of the Attorney General publishes a formula that sets support at 20 percent of net resources for one child and 25 percent for two, up to a cap on net monthly resources that was $9,200 in 2023 ^[1]. Submit an agreed amount 40 percent below that figure with no explanation and a family law judge will start asking questions. Have the worksheet ready and the agreement becomes almost automatic.

There is a plain practical reason too. Knowing the guideline number gives you a real starting point for negotiation. You can agree to go higher, or you can document legitimate reasons to go lower, such as extraordinary medical expenses or a shared custody arrangement that cuts one parent's costs. Either way you are negotiating from facts instead of feelings.

What are the three child support calculation models states use?

States cluster around three formulas. Figuring out which one your state uses tells you exactly which inputs to gather.

Income Shares Model (roughly 40 states, including California, New York, Illinois, Ohio, and Florida ^[2]): Both parents' incomes get added together to find a combined gross income. The state's schedule assigns a total support obligation for that combined income level and the number of children. Each parent pays a proportional share. Earn 60 percent of the combined income and you pay 60 percent of the total, usually as a payment to the lower-earning parent.

Percentage of Income Model (roughly 10 states, including Texas, Alaska, Wisconsin, and Mississippi ^[2]): Only the paying parent's income matters. The state sets a fixed percentage of that parent's net or gross income, and the percentage rises with the number of children. Texas uses net resources; Wisconsin uses gross. Simple, but it ignores the receiving parent's ability to contribute.

Melson Formula (Delaware, Hawaii, and Montana ^[2]): A hybrid that first reserves a subsistence amount for each parent's own minimum needs, then allocates the remaining income to children, then gives parents a share of any surplus. It tracks actual child-rearing costs more closely, but the worksheet is longer.

Not sure which model your state uses? The federal Office of Child Support Services keeps a state-by-state policy map that is updated after each federal review cycle ^[3].

Model	States (approx.)	Key input	Complexity
Income Shares	~40	Both parents' income	Medium
Percentage of Income	~10	Paying parent only	Low
Melson Formula	3 (DE, HI, MT)	Both + subsistence reserve	High

What income figures do you actually plug into the worksheet?

Income is the most disputed number in any child support calculation. Get it right before you file rather than argue about it in a courtroom.

Almost every state starts with gross income from all sources: wages, salary, self-employment income, bonuses, commissions, rental income, investment income, Social Security benefits (excluding SSI), unemployment compensation, and workers' compensation payments ^[4]. The federal Child Support Enforcement program defines income broadly on purpose, so an annual bonus you get in December counts even if it hasn't hit your account when you file.

Self-employment income is gross receipts minus ordinary and necessary business expenses. IRS Schedule C is the standard document, but courts sometimes add back non-cash expenses like depreciation when they believe those deductions cut paper income without cutting actual cash in the parent's pocket.

From gross income, states that use net income (Texas, for example) subtract federal and state income taxes, FICA, mandatory union dues, mandatory retirement contributions, and health insurance premiums paid for the child. That net figure goes into the formula. Income Shares states often apply the formula to gross income directly, then make separate adjustments.

Imputed income matters too. If a parent is voluntarily unemployed or underemployed, the court can assign income based on earning capacity, usually minimum wage at the floor, sometimes more if the parent has documented skills. If you or your spouse recently left a job or cut hours, expect this to come up.

Gather at least the last three months of pay stubs, last year's W-2 or 1099s, and a recent tax return before you sit down with the worksheet. Those three documents cover nearly every question the form asks.

How do you account for parenting time and custody splits?

Custody is often the second-largest variable in the calculation, and it can move the final number a lot.

In Income Shares states, the standard schedule usually assumes primary custody with one parent and visitation with the other. When parents share custody more equally, most states apply an adjustment. California uses a formula with a variable called H (the higher earner's time with the children) and K (a constant derived from income). Increase the higher earner's custody time and the support obligation falls, sometimes steeply ^[5].

Texas, on the Percentage model, makes a flat adjustment. If the noncustodial parent has the child for 100 days or more per year under a standard possession order, the formula applies a multiplier that reduces support by roughly 17 percent ^[1].

For a 50/50 shared custody arrangement in an Income Shares state, the calculation usually runs in both directions: what Parent A would owe Parent B, and what Parent B would owe Parent A. The two amounts get offset, and the parent with the higher theoretical obligation pays the difference. The net transfer can be surprisingly small when incomes and time are roughly equal, which is why some parents in true 50/50 arrangements agree on zero support by consent and get it approved.

Track your proposed parenting schedule in actual overnights per year before you fill out the worksheet. Most worksheets ask for overnights with the noncustodial parent, not percentages, and getting this number wrong throws off your output.

What other costs get added on top of the base support amount?

Base child support covers ordinary day-to-day costs: food, shelter, clothing, routine transportation. The worksheet then stacks three common categories on top of that base.

Health insurance. The cost of the child's share of employer health insurance premiums usually gets added to the total obligation and then split proportionally between parents (Income Shares) or assigned to whichever parent can get coverage most cheaply. If you already cover the child on your plan and your employer charges $280 a month for that coverage, that $280 goes on the worksheet as a credit in your favor.

Uninsured medical and dental expenses. Most courts split extraordinary medical costs (orthodontia, therapy, surgery not covered by insurance) separately from the insurance line. A common split is 50/50 or proportional to income. You will see a checkbox or line item for this on most state worksheets.

Child care costs. Work-related child care (day care, after-school care that lets a parent hold a job) gets added to the obligation in most Income Shares states and then split proportionally. If child care runs $1,200 a month and your combined income means you owe 55 percent of obligations, you owe $660 of that child care cost on top of base support.

Some states also add educational expenses, extracurricular costs, and travel costs for long-distance custody, but those are less standardized. Read your state's guidelines line by line. The federal Office of Child Support Services has links to every state's current guidelines document ^[3].

Where do you find your state's official child support worksheet?

Go to your state court's official website, find the self-help center or family law forms section, and download the worksheet directly. Every state that takes part in the federal Title IV-D program (all 50) must publish guidelines and make worksheets public ^[4]. Most are free PDF downloads. A few states have interactive online calculators that fill in the schedule for you.

Here are reliable starting points by state type:

• Income Shares states: Search "[your state] child support guidelines worksheet" on the state court or state DCSS (Department of Child Support Services) website. California's Judicial Council publishes FL-150 (Income and Expense Declaration), and the DissoMaster formula is what the courts actually use, though a simplified calculator lives at the DCSS site ^[5].
• Texas (Percentage model): The Texas Attorney General's office publishes the formula and an online estimator at texasattorneygeneral.gov ^[1].
• Delaware, Hawaii, Montana (Melson): State judiciary websites carry the multi-step Melson worksheets. They run 3 to 5 pages.

If a search turns up nothing, call your county family court clerk's office. Clerks are required to point you to self-help resources and, in many states, to hand you the forms directly. They cannot give legal advice, but they can give you the right document.

For a full set of state-specific divorce paperwork alongside your support worksheet, DivorceClear's $149 document packet includes state-matched forms built on current court requirements, which saves you the hunt through multiple government websites.

Also bookmark your state's child support calculator page, since many states have made the math interactive.

How do you actually fill out the worksheet step by step?

The exact steps vary by model, but this sequence works for the roughly 40 Income Shares states and adapts to the others.

Step 1: Establish gross income for each parent. Pull last year's tax return and the three most recent pay stubs for each parent. Use the current monthly gross figure, not the annual figure divided by 12, if income swings (hourly workers, seasonal workers, gig workers). Average the last 6 to 12 months for irregular income.

Step 2: Apply allowable deductions (net income states). Subtract taxes, FICA, and mandatory deductions. For most salaried workers, your pay stub already shows net. Just confirm the deductions shown match what the worksheet allows.

Step 3: Add the two parents' incomes. Combined monthly income goes to the state's schedule table. The table shows total child support obligations at each income level, broken out by number of children.

Step 4: Look up the basic obligation. Find the row that matches your combined income and the column for your number of children. This is the total monthly obligation the court expects both parents to share.

Step 5: Calculate each parent's share. Divide each parent's income by the combined income. Multiply each percentage by the total obligation. The noncustodial parent's share is typically the payment amount before adjustments.

Step 6: Add health insurance, child care, and extraordinary medical. Enter the monthly cost of the child's health insurance premium, the monthly work-related child care cost, and any ongoing extraordinary medical expenses. Allocate these proportionally or however your state's worksheet specifies.

Step 7: Apply the parenting time adjustment if it applies. If your custody arrangement qualifies for a shared parenting adjustment (often triggered at 90 to 110 overnights per year with the noncustodial parent, depending on the state), apply the state's multiplier or revised formula.

Step 8: Arrive at the final monthly obligation. Sum the base amount plus add-ons, apply any credits for health insurance paid by the noncustodial parent, and you have the guideline amount. This is the number you put in your divorce agreement and attach to your filing.

That is eight steps, but Steps 3 through 5 take about ten minutes once you have the income figures. The whole worksheet rarely runs longer than 45 minutes with your documents in front of you.

Can you agree to an amount different from what the worksheet says?

Yes, but you have to tell the court why, and that reason needs to be in writing.

Every state lets parents deviate from the guideline amount, but the court has to find that the deviation serves the child's best interest and that the guideline figure would be "unjust or inappropriate" given the circumstances ^[4]. Federal regulations at 45 CFR 302.56 require states to allow rebuttal of the guideline amount and to require written findings when a court order deviates from it ^[4].

Common legitimate reasons to deviate downward: the child has significant uninsured medical needs already covered by one parent outside the formula; the children spend substantially more time with the paying parent than the standard schedule assumes; a parent has extraordinary expenses caring for another child from a prior relationship (not always accepted, but often considered). Common reasons to deviate upward: a child has special educational needs requiring private school or therapy; one parent will carry all transportation costs for long-distance custody.

In an uncontested divorce, the judge's review of your stipulated amount is usually brief. But a number wildly below guideline with no written explanation attached gets your case sent back. Attach the completed worksheet and, if you are deviating, a short written statement of the reason. That combination clears most uncontested cases without a hearing.

Review your divorce papers filing guide too, so the worksheet ends up attached to the right pleading.

How does child support interact with taxes after the divorce?

Short answer: child support payments are not deductible by the payer and not taxable income to the recipient, under current federal law ^[6]. That differs from alimony ordered before 2019, which was deductible, and from alimony ordered after December 31, 2018, which under the Tax Cuts and Jobs Act is also not deductible. Child support and post-2018 alimony now sit in the same tax regime.

Where taxes do touch child support is through the dependency claim and the Child Tax Credit. The IRS lets only one parent claim the child as a dependent in any given tax year. The default rule gives the exemption to the custodial parent (the one with more overnights), but parents can agree in writing to alternate years or to let the noncustodial parent claim in certain years. That agreement has to be memorialized in the divorce decree, and IRS Form 8332 has to be completed by the releasing parent each year ^[6].

The Child Tax Credit (up to $2,000 per child under 17 as of 2025 law) follows the dependency claim, so whichever parent claims the dependent gets the credit. For parents with roughly equal incomes, deciding who claims in which years can be worth a meaningful amount every year, and it is a legitimate reason to nudge support in a written agreement.

What if your income or custody changes after the order is filed?

A child support order is not permanent. It is modifiable when there is a substantial change in circumstances, which most states define as a 15 percent or greater change in the guideline amount, a major change in custody, or a big change in either parent's income ^[3].

The process is to file a motion to modify in the same court that issued the original order. Some states let you use an administrative process through the state child support agency instead of returning to family court, which is faster and cheaper. If you and your ex agree on the new amount, you can file a stipulated modification, which works just like the original agreement process.

Here is the trap. The modification is only effective from the date the court approves it, not from the date the circumstances changed. If your income dropped six months ago and you still haven't filed, you owe the full original amount for those six months. File as soon as a qualifying change happens.

For self-employed parents or anyone with variable income, many states review the order every three years automatically, triggered by either parent requesting a review through the state IV-D agency. This costs nothing and can adjust the order without either party hiring a divorce attorney.

What mistakes do people make on the child support worksheet?

A handful of errors show up again and again in self-filed cases.

Wrong income figure. Using take-home pay (net) when the formula calls for gross, or using gross when it calls for net. Read the top of your state's worksheet. It says which one. Using the wrong figure can swing your output by 20 to 30 percent.

Forgetting secondary income. A part-time job, rental income, or freelance work that isn't on a W-2 still counts. Courts can pull bank statements or tax returns and impute income from deposits.

Wrong custody numbers. Estimating overnights instead of counting them from the actual proposed parenting plan. A difference of 15 overnights per year can move you across the threshold for a shared parenting adjustment in some states.

Leaving out child care. Parents often skip work-related child care on the worksheet because it feels like a separate issue. It isn't. It goes on the worksheet and changes the final number.

Using an outdated worksheet. State guidelines get reviewed at least every four years under federal law ^[4]. A 2019 worksheet may carry different income brackets or percentages than the current one. Download a fresh copy from the state court website every time.

Leaving the worksheet unsigned or undated. Most states require both parents to sign, or at least the filing parent to certify the information is accurate. An unsigned worksheet is an incomplete filing.

Not sure you got it right? Your county court's self-help center can check your math without giving legal advice. That service is free in most jurisdictions.

What does a completed child support worksheet look like in practice?

A concrete example helps. Take a hypothetical Income Shares state where Parent A earns $5,000 gross per month and Parent B earns $3,000 gross per month. They have one child. Parent B has primary custody (270 overnights), Parent A has 95 overnights.

Step 1: Combined gross income = $8,000/month. Step 2: The state schedule for $8,000 combined income and one child shows a basic obligation of $1,240/month. Step 3: Parent A's share = $5,000 / $8,000 = 62.5%. Parent A owes 62.5% x $1,240 = $775/month as the base. Step 4: Parent B carries the child on employer health insurance at $195/month attributable to the child. That gets split: Parent A owes 62.5% x $195 = $122/month for insurance; Parent B's share is $73/month. Step 5: Monthly work-related child care is $600/month. Parent A's share: $375; Parent B's share: $225. Step 6: Total monthly obligation from Parent A to Parent B: $775 (base) + $122 (insurance) + $375 (child care) = $1,272/month. Parent B's own contributions ($73 insurance + $225 child care = $298) are treated as satisfied by the coverage and care she already pays. Step 7: At 95 overnights, Parent A sits just under the 100-overnight threshold that would trigger a shared parenting adjustment in a state like Texas, so no adjustment applies. Step 8: Final order amount: $1,272/month.

That is a real worksheet run, not a magic number. Your numbers will differ, but the logic is the same. Plug in real income, find the schedule, split proportionally, add actual costs.

For people filing their own uncontested divorce who want every form in one place, DivorceClear's document packet is built for exactly this.

Frequently asked questions

Do I have to attach a child support worksheet to my divorce filing?

In most states, yes. The worksheet or a financial disclosure form is a required exhibit to your divorce agreement wherever children are involved. Some states accept just the agreed dollar amount in the decree if both parents sign, but courts increasingly want to see the underlying math. Check your state court's family law filing checklist, usually on the self-help center page, before you submit.

What's the fastest way to get a rough child support estimate before filling out the full worksheet?

Use your state's official online calculator if one exists. Texas, California, Colorado, and many other states have free web tools on state agency websites that run the guideline formula with inputs you type in. They aren't legally binding and don't replace the signed worksheet, but they give you a defensible ballpark in under five minutes and show which variables matter most for your situation.

Does overtime count as income for child support purposes?

Usually yes. Most state guidelines include overtime in gross income, especially when it's regular and predictable. Courts look at the pattern: if you've worked 10 hours of overtime every week for two years, that overtime will likely count. Truly voluntary, one-time overtime that can't be counted on is sometimes excluded, but you'd need to show that to the court with a pay history. When in doubt, include it and let the worksheet speak.

How does 50/50 custody affect the child support calculation?

In Income Shares states, true 50/50 custody (182 or 183 overnights each) typically triggers a shared parenting calculation where each parent's theoretical obligation is offset against the other's, and only the net difference transfers. When incomes are similar, this can produce a very small payment or even zero. Courts can approve a zero-support order in a genuine 50/50 arrangement, but you have to document it on the worksheet, more than assert it.

Can a parent claim zero income if they're not working?

Not automatically. Courts can impute income to a voluntarily unemployed or underemployed parent based on earning capacity. At minimum, most courts impute at least minimum wage for a full-time work week. If unemployment is involuntary (layoff, disability, recent graduation), courts are more flexible, but you'll still need documentation. A parent who quit a job to dodge paying support is the clearest case for imputed income.

Are private school tuition or extracurricular fees included in the child support worksheet?

Base child support covers ordinary costs and does not automatically include private school or activities. These are typically handled as a separate written agreement or court order. Some states have a worksheet add-on for educational expenses, but it's discretionary, not automatic. If you and your spouse agree to split those costs, put it in the decree separately and be specific about which school and which activities are covered.

What happens if one parent refuses to provide income information?

In a contested case, you'd subpoena financial records. In an uncontested divorce, both parents typically sign a financial disclosure form under penalty of perjury, which is the main check. If you later discover your ex understated income, most states allow a retroactive modification when you can show fraud or material misrepresentation. That's a reason to be careful with the income figures in your original agreement, not a reason to skip the worksheet.

How often can child support be modified after the order is issued?

Most states allow modification any time there's a substantial change in circumstances, usually defined as a 15 percent or more change in the guideline amount. Federal law requires states to review orders on request every three years for families in the IV-D program, which covers most court-ordered support cases. You can also agree to a modification with your ex and file it as a stipulated order without a contested hearing.

Does child support automatically end at age 18?

It depends on your state. Many states end support at 18 or upon high school graduation, whichever comes later, often capping out at 19. Some states extend support through college if the child attends full-time and the parents have the income. A few states let agreements extend support beyond the statutory minimum. Check your state's termination statute and put the termination date explicitly in your decree.

Is child support calculated differently for high-income parents?

Yes. Most states cap the income range in their schedule table, and above that cap the court has discretion. In Texas, net resources above roughly $9,200 per month are excluded from the standard percentage formula, and the court looks at the child's proven needs instead. In Income Shares states, schedule tables typically top out at combined incomes of $20,000 to $30,000 per month, above which a judge sets the amount based on the child's actual expenses and lifestyle.

What's the difference between the child support worksheet and a parenting plan?

The worksheet is purely a financial calculation document that produces the monthly dollar amount. A parenting plan (also called a custody agreement or parenting schedule) sets the custody arrangement, decision-making rights, holiday schedules, and communication rules. You need both for a complete filing. The parenting plan's custody breakdown feeds into the worksheet's parenting time adjustment, so finish the parenting plan first, then use those overnights on the worksheet.

Do I need a lawyer to fill out the child support worksheet?

No. The worksheet is a math document, not a legal argument. If your finances are straightforward (salaried employees, clear custody arrangement, no significant assets or business income), you can fill it out yourself using official state instructions. A lawyer earns their fee when income is disputed, when a parent is self-employed, or when one parent believes the other is hiding assets. For a clean uncontested case, the worksheet is genuinely a do-it-yourself task.

Where can I get free help filling out the child support worksheet?

Your county family court's self-help center is the best first stop. These centers exist to help self-represented parties complete required forms, and staff can review your math without giving legal advice. Many state bar associations run free family law clinics. Legal aid organizations serve lower-income filers. Your state child support enforcement agency (often called DCSS or OAG) can sometimes run the calculation for you at no cost.

Sources

1. Texas Office of the Attorney General, Child Support Division: Texas sets support at 20% of net resources for one child, 25% for two, with a net resources cap and a possession-order reduction for 100+ days of custody.
2. National Conference of State Legislatures, Child Support Guideline Models by State: Roughly 40 states use Income Shares, about 10 use Percentage of Income, and 3 states (Delaware, Hawaii, Montana) use the Melson Formula.
3. U.S. Department of Health and Human Services, Office of Child Support Services: The federal OCSS maintains state policy comparisons, links to state guidelines, and information on the triennial review requirement for child support orders.
4. Code of Federal Regulations, 45 CFR Part 302 (Establishment of Support Guidelines): Federal regulations require all Title IV-D states to publish support guidelines, review them at least every four years, and allow written rebuttal when a court order deviates from the guideline amount.
5. California Courts Self-Help Center (DissoMaster and Child Support Information): California uses the Income Shares model with a custody time variable (H) that reduces the higher earner's support obligation as their custody time increases.
6. IRS Publication 504, Divorced or Separated Individuals: Child support payments are not deductible by the payer and not taxable income to the recipient; the dependency claim follows the custodial parent unless Form 8332 is signed.
7. U.S. Department of Health and Human Services, Office of Child Support Services (Annual Report to Congress): Federal annual data on child support collections, caseloads, and state performance metrics, including average support orders by state.
8. Delaware Courts, Family Court Child Support Information (Melson Formula): Delaware uses the Melson Formula, which reserves a subsistence amount for each parent before allocating remaining income to children.