Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Estimated monthly support (midpoint)
$1,681
Low end of range
$1,428
High end of range
$1,933
Annual estimate (midpoint)
$20,167
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How to use this
- 1Enter parent a monthly gross income ($).
- 2Enter parent b monthly gross income ($).
- 3Enter number of children.
- 4Enter parent b overnight parenting time (%).
- 5Enter monthly childcare + health premium ($).
- 6Read your estimated monthly support (midpoint) on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Most states use an 'income shares' model that combines both parents' incomes, applies that combined income to a state schedule to find the total support obligation for the number of children, then splits that obligation proportionally by each parent's share of combined income. A minority of states use a flat 'percentage of income' model based only on the paying parent's income. This calculator applies a simplified income-shares approximation, using a basic obligation table roughly modeled on common state schedules, then adjusts for parenting time (many states reduce the obligation when the paying parent has substantial overnight custody) and adds typical add-ons for childcare and health insurance premiums split proportionally. Treat the output strictly as a ballpark starting point, not a legal figure, since every state's actual formula, worksheets, and deviation factors differ and only a state's official calculator or family law attorney gives you an authoritative number.
Worked example
Using the values the calculator loads with:
Inputs
- Parent A monthly gross income: 5500 $
- Parent B monthly gross income: 3500 $
- Number of children: 2
- Parent B overnight parenting time: 20 %
- Monthly childcare + health premium: 500 $
Results
- Estimated monthly support (midpoint): $1,681
- Low end of range: $1,428
- High end of range: $1,933
- Annual estimate (midpoint): $20,167
What each field means
Inputs
- Parent A monthly gross income ($)
- The parent a monthly gross income used in the calculation, measured in $. Starts at 5500 $ so you have a working example on load.
- Parent B monthly gross income ($)
- The parent b monthly gross income used in the calculation, measured in $. Starts at 3500 $ so you have a working example on load.
- Number of children
- The number of children used in the calculation. Starts at 2 so you have a working example on load. Accepted range: 1–6.
- Parent B overnight parenting time (%)
- The parent b overnight parenting time used in the calculation, measured in %. Starts at 20 % so you have a working example on load. Accepted range: 0–100 %.
- Monthly childcare + health premium ($)
- The monthly childcare + health premium used in the calculation, measured in $. Starts at 500 $ so you have a working example on load.
Results
- Estimated monthly support (midpoint)
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Low end of range
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- High end of range
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual estimate (midpoint)
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why is this only a range and not an exact figure?
Every state publishes its own obligation tables, deviation factors, and treatment of items like extraordinary medical expenses or private school tuition, and small differences in those rules move the real number meaningfully. This tool approximates the common income-shares logic; only your state's official worksheet produces a legally usable figure.
Does parenting time really change the amount?
In most income-shares states, yes, once the paying parent has the child a substantial portion of overnights (commonly 20%+ or more depending on the state's threshold), the obligation is reduced to reflect that they're directly covering costs during that time rather than only paying support.
Are childcare and health insurance always added on top?
Typically yes, work-related childcare and the child's portion of health insurance premiums are added to the base obligation and then split proportionally by income share, not absorbed by whichever parent happens to pay the provider directly.
Can support be modified later?
Yes, when there's a substantial change in circumstances, commonly defined as roughly a 15-20% change in either parent's income, a change in custody arrangement, or a change in the child's needs. Either parent can petition the court to recalculate under the current guideline at that point.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Child Support Guideline Range Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/child-support-guideline-range
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/child-support-guideline-range" target="_blank" rel="noopener">Child Support Guideline Range Calculator — RevenueLab</a> (2026).</p>
Source: [Child Support Guideline Range Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/child-support-guideline-range) (2026).