Child Support Calculator for Fathers — Know Your Number Before Court Does
Enter your income and custody details. Get an estimated monthly payment using your state's formula — in under 60 seconds.
✓ Free — no login required
✓ Based on state guidelines
✓ Used by Dads in all 50 states
✓ Results stay private
Most Dads walk into a child support hearing without running the numbers first. They find out what the court calculated after the order is signed — not before. This calculator gives you the estimate before anything is filed, so you know what to expect, what to challenge, and whether your income figure is being calculated correctly.
Child support is calculated using a formula — not a judgment call. Every state has one. The inputs are your gross income, your co-parent's gross income, the custody schedule, and certain adjustments like health insurance and childcare. Plug in the right numbers and the formula produces the support amount. This tool runs that calculation so you see it the same way the court does.
Child Support Estimator
Results are estimates based on state guidelines · Not legal advice
The One Number Most Dads Enter Wrong — Before They Even Start
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Select your stateEach state uses its own formula. The calculation is different in Texas than it is in California. Pick your state first — everything else adjusts from there.
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Enter your gross income — not take-home payThis is the most common mistake Dads make. Child support is calculated on gross income — what you earn before taxes, retirement contributions, and health insurance are deducted. Use your gross monthly amount, not what hits your bank account.
3
Enter your co-parent's gross incomeIn most states, both parents' incomes go into the formula. If you don't know the exact number, use your best estimate — you can run the calculator multiple times with different figures.
4
Enter the custody splitThe percentage of overnights your child spends with each parent affects the calculation in most states. Use actual nights, not a general description like "every other weekend."
5
Add adjustments if applicableHealth insurance premiums you pay for the child, childcare costs, and other court-recognized expenses can reduce your obligation. Enter what applies to your situation.
⚠ Use Gross Income — Not What You Take Home
The single most common error in self-calculated support estimates: using net income instead of gross. On a $70,000 salary, that gap is typically $18,000–$22,000 in income. The wrong income figure produces the wrong estimated amount — and if you file a modification using the wrong number, the court recalculates and your case may not meet the threshold for approval.
Gross vs. Take-Home — The Gap That Breaks Most Self-Calculated Estimates
Wrong — gap looks smaller than it is · case denied
ChildCustodyPros.com · Use your W-2 Box 1 figure ÷ 12 for the most accurate monthly gross
What Your Result Actually Tells You
If the number is close to what you're paying now
Your current order may already reflect accurate income figures. A modification may not produce enough of a change to meet your state's threshold — typically 10–15%.
If the number is lower than what you pay now
You may qualify for a downward modification. The gap between your current order and the estimated amount determines whether you meet the threshold to file.
If the number is higher than what you pay now
Your co-parent could potentially file for an upward modification. Don't request a review without running this calculation first — it can go both ways.
If the result surprises you
Check your inputs — especially gross vs. net income and the custody percentage. Small input errors produce large result differences. Run it again with verified figures.
Why Your State's Formula May Surprise You — Even With Equal Custody
About 40 states use the income shares model. Both parents' gross incomes are combined. The state determines how much money children at that combined income level need. Each parent is responsible for their proportional share — the higher earner pays more, regardless of custody time.
About 10 states use the percentage of income model. Only the paying parent's income matters. A fixed percentage — typically 17% for one child, 25% for two — is applied to gross income. The co-parent's income doesn't directly affect the number.
Custody time adjustments reduce the amount in most states once parenting time exceeds a threshold — commonly 30–40% of overnight time. Below that threshold, time adjustments may not apply. This is why 50/50 custody doesn't automatically produce zero support — the income differential between the two parents still drives the calculation.
Run It Both Ways Before Any Hearing
Run this calculator with your income figures and with your co-parent's most current income. Courts calculate both. If her income has increased significantly since your order was entered, that change works in your favor on a modification or 3-year review — even if your income hasn't changed.
What This Number Doesn't Show — and What to Do About It
This tool estimates the base support amount. It doesn't include add-ons that courts sometimes order separately — college expenses, extracurricular activities, travel costs for custody exchanges, or special needs care. It also doesn't account for arrears already owed. The monthly support figure and the arrears balance are two separate numbers.
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The number that changed what he filed:He'd been calculating his support estimate using his take-home pay — $4,100/month. He plugged it into the state calculator and got a proposed new amount that was $190 less than his current order. He thought that was the gap. Then he ran it with his gross income — $5,800/month. The formula produced a different result. The difference between the two calculations was $340/month — not $190. When he filed using the correct gross income figure, his modification was approved. The calculator told him the right number. He'd just been entering the wrong income.
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When the estimate was higher than the current order:She ran the calculator before filing a modification request. Her co-parent's income had increased significantly since their original order — she knew that. What she didn't expect was that the income shares formula, run with both current incomes, actually produced a lower support obligation for him than what he was currently paying. The current order was already above guideline. She brought this to her attorney. They chose not to file the modification — because filing would have required disclosing both incomes and could have triggered a downward adjustment. Running the calculator first saved months of costly litigation.
Questions Dads Ask Before Using This Calculator
Is this calculator accurate?
It produces an estimate based on your state's published guidelines. The actual amount a court orders depends on income documentation both parties submit, any contested figures, and judicial discretion on adjustments. Use this as a planning tool — not as a guarantee of what a court will order.
What if I don't know my co-parent's exact income?
Use your best estimate and run it a few times with different figures to see how sensitive the result is. In a formal modification proceeding, both parties must submit income documentation — you can request it through the discovery process. For planning purposes, an estimate gets you directionally accurate.
I'm self-employed. Should I use my net income from my tax return?
No — and this is critical. Courts calculate self-employment income as gross business revenue minus legitimate business expenses. That number is typically higher than your Schedule C net income because courts add back depreciation, home office deductions, and other non-cash expenses. Use your gross business revenue minus verifiable cash expenses for the most accurate estimate.
Does overtime count as income for child support?
Usually yes — if it's regular and ongoing. Courts average recurring overtime over 2–3 years. If the overtime was a one-time project that ended, document that it was non-recurring and run the calculator without it. Enter the income figure you can actually defend with documentation.
I have 50/50 custody. Will my result be close to zero?
Only if both parents earn similar incomes. Equal parenting time reduces the support amount — it doesn't eliminate it when there's a meaningful income gap. If you earn $85,000 and your co-parent earns $30,000, you'll likely owe support even with a 50/50 schedule. Run your actual numbers to see where you land.
My result is lower than what I currently pay. What do I do?
That gap may be grounds for a modification — if the difference between your current order and the estimated amount meets your state's threshold (typically 10–15%). The Child Support Reduction Guide walks you through the exact filing process. Courts don't backdate reductions, so the sooner you file, the sooner the lower amount takes effect.
Can I use this result in court?
This tool produces an estimate, not a court-ready document. At a hearing, both parties submit financial affidavits and income documentation. The court calculates the amount from verified figures — not from a calculator printout. Use this tool to prepare and verify your understanding of what the formula should produce.
Curiosity · ChildCustodyPros.com
The Calculator Shows You the Number. The Guide Shows You How to File for It.
He ran the calculator three times. Each time it came back at $340/month — his current order says $680. The gap is real. The income figures are correct. He qualifies. He just doesn't know which forms to file, which court to file in, or what documentation prevents the most common denial reason. The number is the easy part. The filing is where most Dads get stuck.
The Child Support Reduction Guide takes you from the number this calculator produced to a correctly filed modification — step by step, state by state. Every month between now and your filing date posts at the old amount permanently. Courts don't backdate.
See exactly which income triggers courts accept for a downward modification
Understand the filing window — and what every month of delay costs permanently
The pre-filing checklist that prevents the most common denial reason
State-specific instructions — right court, right forms, right sequence
How to verify your income calculation matches what the court will use
The modification only runs from your filing date. Every month you wait is a month permanently overpaid. childcustodypros.com
For informational and educational purposes only. This calculator produces estimates based on publicly available state child support guidelines. Results are not legal advice and do not account for all factors a court may consider. Always consult a licensed family law attorney for your specific situation. ChildCustodyPros.com does not provide legal advice.
