Michigan Child Support Calculator (2026)
Estimate monthly child support under the 2025 Michigan Child Support Formula. Enter both parents’ incomes and this tool applies the General Care Equation, the parental time offset, the low-income threshold rules, and each parent’s share of medical costs and child care.
Calculate Michigan Child Support
Michigan’s formula runs on monthly net income. If you know each parent’s monthly net income as Michigan defines it, enter it directly. Estimated mode subtracts only federal tax and FICA — see the assumptions below.
Before taxes. Label the parents consistently — Parent A’s overnights go in the overnights field below.
The 2025 supplement publishes General Care tables for one to five children. For six or more children the formula’s table treatment is not published in the supplement — a court or the Friend of the Court must work those cases out, so this tool covers one to five.
Nights the children sleep at Parent A’s home. Parent B’s overnights are the rest of the year (365 minus this number). The parental time offset uses both.
Work- or education-related child care for these children, before any subsidy.
Michigan allocates the actual cost: gross cost minus subsidies, tax credits and reimbursements. Enter the monthly amount of any of those here.
Only the children’s share of the premium (total premium divided by everyone covered, times the children in this case).
How to read this: the adjustments are shown as amounts that increase (or, when negative, decrease) what Parent B pays Parent A, and the total gives the single monthly payment and its direction. The premium and child care adjustments settle each parent’s income share of those costs against what they already pay directly. Base support obligations are rounded to the nearest dollar, as the manual directs.
How Michigan Calculates Child Support
Michigan uses the Michigan Child Support Formula (MCSF), developed under MCL 552.519 and published in the 2025 MCSF Manual with economic data in the 2025 MCSF Supplement. Support is apportioned between the parents based on each parent’s percentage share of their combined monthly net income (MCSF 3.01(B)) — it is not a flat percentage of one parent’s pay. A parent’s total obligation has three parts: base support, medical support, and child care (MCSF 3.01(A)). The steps are:
- Find each parent’s monthly net income. Michigan starts from all income and subtracts only the deductions the manual allows — actual income taxes and FICA first, then items such as mandatory union dues or required retirement contributions (MCSF 2.07). This “net income” is deliberately not the same as take-home pay.
- Combine the incomes — with a low-income exception. Monthly net family income includes a parent’s income only if it exceeds the Low Income Threshold of $1,255 a month (MCSF 3.02(B)(1)). A parent at or below the threshold is handled by the low-income rules described below.
- Run the General Care Equation (MCSF 3.02(B)) using the General Care Support Table for the number of children, to get the family’s total base support.
- Split base support by income share. Each parent’s base support obligation is the total base support times that parent’s percentage share of combined net income, rounded to the nearest dollar.
- Apply the parental time offset (MCSF 3.03), which weighs each parent’s obligation by the other parent’s overnights and produces the single base-support payment between the parents.
- Add medical support and child care (MCSF 3.04–3.06): ordinary medical expenses, the children’s health insurance premium, and actual child care costs are apportioned by income share and netted against what each parent already pays.
A = base support at the table row B = marginal percentage C = monthly net family income D = the table row’s income level E = a parent’s income share G = that parent’s base support obligation
Parental Time Offset (MCSF 3.03): [ (Ao)^2.5 × Bs − (Bo)^2.5 × As ] ÷ [ (Ao)^2.5 + (Bo)^2.5 ]
Ao / Bo = annual overnights with Parent A / Parent B As / Bs = each parent’s base support obligation. A negative result means Parent A pays; a positive result means Parent B pays.
Worked Example: $6,000 and $4,000 Gross Monthly Incomes, 2 Children
| Step | Calculation | Result |
|---|---|---|
| Parent A net income (est.) | $72,000/yr gross minus est. federal tax $7,010 and FICA $5,508 | $4,956.83/mo |
| Parent B net income (est.) | $48,000/yr gross minus est. federal tax $3,580 and FICA $3,672 | $3,395.67/mo |
| Monthly net family income | $4,956.83 + $3,395.67 (both parents above the $1,255 threshold) | $8,352.50/mo |
| Total base support (2 children) | Table row $7,148.44: $2,080.91 + 20.20% × ($8,352.50 − $7,148.44) | $2,324.13/mo |
| Income shares | Parent A 59.35% / Parent B 40.65% of combined net income | — |
| Base support obligations | $2,324.13 × each share, rounded to the nearest dollar | A: $1,379 B: $945 |
| Base support after offset | 292 overnights with A, 73 with B, run through the MCSF 3.03 offset | $874.58 — B pays A |
| Ordinary medical | 2 children = $400/year ($33.33/mo); B’s 40.65% share | $13.55 |
| Health premium | $300 total premium; B’s share $121.96 minus the $100 B already pays | $21.96 |
| Child care | $800 cost − $200 subsidy = $600 actual cost; B’s 40.65% share | $243.93 |
| Estimated support | $874.58 + $13.55 + $21.96 + $243.93 | $1,154.02/mo — Parent B pays Parent A |
The General Care Support Tables (2025 MCSF-S)
The 2025 MCSF Supplement (Section 2.03(C)) publishes the complete General Care tables below. To use them, find the highest income level that does not exceed the family’s monthly net income: total base support equals that row’s base support plus the row’s marginal percentage of the income above the row’s level. The tables exclude medical and child care costs, which are added afterwards.
| Monthly Net Family Income | 1 Child | 2 Children | 3 Children | 4 Children | 5 Children |
|---|---|---|---|---|---|
| $2,000.00 | $500.00 | $762.00 | $920.00 | $1,026.00 | $1,130.00 |
| $3,250.00 | $811.53 | $1,235.98 | $1,491.43 | $1,663.35 | $1,831.70 |
| $4,500.00 | $1,031.85 | $1,539.90 | $1,809.90 | $2,015.10 | $2,224.80 |
| $7,148.44 | $1,403.95 | $2,080.91 | $2,448.34 | $2,730.70 | $3,005.20 |
| $9,366.93 | $1,714.15 | $2,529.07 | $2,978.68 | $3,325.26 | $3,653.10 |
| $17,747.86 | $2,720.75 | $4,026.99 | $4,736.90 | $5,276.44 | $5,817.75 |
| Marginal % over that level | 1 Child | 2 Children | 3 Children | 4 Children | 5 Children |
|---|---|---|---|---|---|
| Over $2,000.00 | 24.92% | 37.92% | 45.71% | 50.99% | 56.14% |
| Over $3,250.00 | 17.63% | 24.31% | 25.48% | 28.14% | 31.45% |
| Over $4,500.00 | 14.05% | 20.43% | 24.11% | 27.02% | 29.47% |
| Over $7,148.44 | 13.98% | 20.20% | 23.91% | 26.80% | 29.20% |
| Over $9,366.93 | 12.01% | 17.87% | 20.98% | 23.28% | 25.83% |
| Over $17,747.86 | 11.29% | 16.16% | 18.19% | 20.44% | 22.34% |
A note on the one-child table: in the official supplement, the second row of the One Child table prints its marginal percentage as applying “over $3,500.00,” although the row’s income amount is $3,250.00 and every other row in all five tables applies its percentage over the row’s own amount — which is also how MCSF 3.02(B) defines the calculation. The arithmetic confirms it: $811.53 plus 17.63% of ($4,500 − $3,250) is $1,031.91, matching the next row’s printed base support of $1,031.85 within rounding, while measuring from $3,500 would give $987.83. This calculator follows the table’s own pattern and applies the percentage over $3,250 for that row.
Above the top level, income is normally still run through the equation using the top row (MCSF 3.02(B)); only at extremely high incomes does the court step in with its own discretion (MCSF 3.02(E)). There is no hard income cap in the Michigan formula. The supplement publishes tables for one to five children only, which is why this calculator stops at five.
The Parental Time Offset
Once each parent’s base support obligation is set, Michigan adjusts for parenting time with the offset in MCSF 3.03. Each parent’s obligation is weighted by the other parent’s overnights raised to the 2.5 power — a deliberately steep curve. A parent with few overnights sees almost no reduction; as time approaches an even split, the payment shrinks quickly; at exactly equal overnights and equal obligations it reaches zero. The offset is used whenever the approximate annual overnights with each parent can be determined, and every support order must state whether an offset was included and the number of overnights used. If the overnights actually exercised later differ from those used by 21 or more overnights, that difference can support a modification (MCSF 3.03(D)). The offset does not apply when a non-parent has custody of the children.
Low Incomes: the $1,255 Threshold, the 10% Rule, and the Transition
Michigan protects low-income parents through the Low Income Threshold of $1,255 per month (2025 MCSF-S 2.01(A), based on the 2024 federal poverty guideline) instead of a self-support reserve:
- At or below the threshold, a parent’s base support is simply 10% of that parent’s own monthly net income — the Low Income Equation (MCSF 3.02(C)), designed to leave the parent enough to subsist on. That parent’s income is also left out of the family income used to work out the other parent’s obligation (MCSF 2.09(B)).
- Just above the threshold, the Low Income Transition Equation (MCSF 3.02(D)) phases the obligation in: T = ($1,255 × 10%) + [(monthly net income − $1,255) × P], where P is 50% for one child, 55% for two, 60% for three, 65% for four, and 70% for five or more. The court calculates both the transition result and the General Care result and uses the transition figure when it is lower. This calculator does the same comparison automatically.
The difference is large. A parent with $1,100 of monthly net income and one child owes $110 under the low-income equation; the plain General Care calculation would have produced roughly $265 on the same facts. A court may also apportion an incapacitated parent’s obligation down to zero in appropriate cases.
Medical Support and Child Care
Ordinary medical expenses (MCSF 3.04, amounts in 2025 MCSF-S 2.02) are presumed at $200 per child per year — $200 for one child, $400 for two, $600 for three, $800 for four, and $1,000 for five or more — and the paying parent’s income share of that amount is built into the monthly order. Uninsured expenses above the ordered ordinary amount (“additional medical”) are split between the parents by the same income percentages as they arise. Courts may add amounts for predictably higher expenses, such as orthodontia or special needs.
Health care coverage (MCSF 3.05): the court orders a parent to maintain coverage for the children when it is accessible and available at a reasonable cost — reasonable cost means the children’s net premium does not exceed 6% of the providing parent’s gross income. The children’s share of the premium is apportioned by income share and, after the parental time offset, the difference between what a parent should bear and what they already pay is added to or subtracted from support. That netting is exactly what the premium fields in this calculator do.
Child care (MCSF 3.06): actual child care expenses that let a parent look for work, keep work, or attend an education program are allocated by income share. “Actual” means the gross cost minus any subsidies, tax credits (including the federal child care credit), and reimbursements — which is why the calculator asks for a subsidy amount. The need for child care is presumed to continue until the last day of the month in which the youngest child turns 13.
How This Calculator Estimates Net Income
Michigan’s formula runs on net income as the manual defines it, and courts deduct actual income taxes — federal and Michigan — plus FICA, and then the other items MCSF 2.07 allows (mandatory employment payments, certain court-ordered life insurance premiums, a parent’s own mandatory health coverage cost, and similar items). A parent who supports additional children from another relationship also gets an Additional Children Adjustment, multiplying their remaining net income by 83% (one additional child), 75% (two), 68% (three), 64% (four), or 60% (five or more) (MCSF 2.08). Courts can also count potential income for a parent who is voluntarily unemployed or underemployed.
This calculator’s estimated mode annualizes the gross figure you enter and subtracts only 2026 federal income tax — single-filer brackets with the $16,100 standard deduction — and Social Security and Medicare (7.65% combined, Social Security capped at the $184,500 wage base). It does not deduct Michigan income tax or any of the other 2.07 items, and it does not apply the additional-children adjustment, so estimated net incomes run somewhat higher than a court’s figures and the estimate tends to run high as well. For a closer result, switch to direct entry and use each parent’s monthly net income worked out under the manual’s rules.
