Child support · MI
Michigan child support calculator
The Michigan Child Support Formula of the State Court Administrative Office, worked through with real numbers.
Rules read on official Michigan pages on · Checked by Radif Partners · How we calculate
- Model
- State formula
- Income counted
- Net income
- Shared parenting
- No fixed formula
- 1 child, $5,000 / $3,000
- $954
- a month
Michigan has no lookup table: the Michigan Child Support Formula computes base support from the parents' combined net income with a band equation, and a parent with $5,000 of monthly net income facing $3,000 owes $1,411 a month for two children when the children sleep at the other home every night. The equation takes a base amount and a marginal percentage from the band that holds the family's income, multiplies by the parent's share rounded to a hundredth of a percent, and rounds to the dollar. Overnights then enter through the parental time offset, which raises each parent's yearly overnights to the power 2.5: 100 nights bring the same order to $1,229, 146 nights to $810. Parents at or below the $1,255 Low Income Threshold pay 10% of net income, and those just above it are protected by a transition equation. The 2025 manual and supplement remain the current guideline in 2026.
Guideline child support in Michigan, per month
$954
$11,448 a year
| Family net income counted | $8,000 |
| General care support, 1 child | $1,526 |
| Paying parent’s base support | $954 |
| Other parent’s base support | $572 |
| Paying parent’s share of combined net income | 62.5% |
Estimate under the Michigan guideline as published, from the incomes you enter. Deviations, imputed income, other children and the judge's findings can change the order. How this is calculated.
6 bands instead of a schedule
The State Court Administrative Office publishes, for each number of children, a General Care Support Table of only 6 lines. Each line gives an income amount, a base support figure and a marginal percentage. Find the last line whose income amount does not exceed the family's net income, add the marginal percentage of the excess to the base support, and you have the family's general care figure. For two children the lines start at $2,013.94 and end at $17,871.57; above that last line the same equation simply continues, though the court may use discretion when income greatly exceeds it.
Our family has $8,000 of combined net income, so the line at $7,198.27 applies: $2,095.42 plus 20.2% of the amount above $7,198.27, or $2,257 in all. The parent earning $5,000 carries 62.5% of it, which rounds to $1,411. Nothing else in the formula uses a table lookup.
The offset curve
Michigan computes base support for both parents, then nets them against time. The offset is (Ao2.5 × Bs − Bo2.5 × As) ÷ (Ao2.5 + Bo2.5), where Ao and Bo are overnights and As and Bs each parent's base support. A negative result means parent A pays. There is no minimum number of nights before it applies:
| Overnights with the paying parent | Monthly base support |
|---|---|
| 0 | $1,411 |
| 52 | $1,386 |
| 100 | $1,229 |
| 146 | $810 |
| 182 | $290 |
The power makes early nights cheap and late nights expensive. A weekly overnight barely moves the order, while the stretch toward equal time cuts it fast. Because every order must state the number of overnights it used, a gap of 21 or more between that number and actual practice is a ground to ask the friend of the court for a review.
The threshold and the transition
A parent whose net income is at or below $1,255 (the 2024 federal poverty guideline the supplement adopted) pays 10% of that income, and that income is dropped from the family total used for the other parent. Just above the threshold, a second equation competes with the band formula: 10% of the threshold plus a percentage of the income above it (50% for 1, 55% for 2, 60% for 3, 65% for 4 and 70% for 5 or more children). The parent pays whichever is lower. A parent at $1,600 next to one at $3,000 would owe $544 under the band equation, but the transition caps base support at $315.
Child care and health premiums are then divided by each parent's share of income, and the formula adds an ordinary medical amount per child that this estimate leaves to the order. The state-by-state calculator lets you compare Michigan's curve with table states.
The Michigan guideline this calculator applies
| Rule | Michigan |
|---|---|
| Model | Michigan Child Support Formula: general care equation on family net income bands (base amount + marginal percentage) |
| Income counted | Net income: after income taxes and mandatory deductions, as the state defines it. |
| Shared parenting | No overnight formula in the calculator (see the rule below) |
Monthly support for one paying parent, the other parent without income
| Paying parent’s monthly income | 1 child | 2 children | 3 children | 4 children |
|---|---|---|---|---|
| $2,000 | $498 | $535 | $573 | $610 |
| $3,000 | $749 | $1,085 | $1,173 | $1,260 |
| $4,000 | $945 | $1,421 | $1,687 | $1,880 |
| $5,000 | $1,105 | $1,646 | $1,936 | $2,156 |
| $6,000 | $1,245 | $1,851 | $2,177 | $2,426 |
| $8,000 | $1,526 | $2,257 | $2,657 | $2,965 |
| $10,000 | $1,794 | $2,648 | $3,119 | $3,481 |
| $12,500 | $2,095 | $3,095 | $3,643 | $4,063 |
| $15,000 | $2,395 | $3,542 | $4,168 | $4,645 |
| $20,000 | $2,980 | $4,399 | $5,157 | $5,748 |
How the amount is set. Base support (2025 MCSF 3.02): family net income C = sum of the parents' monthly net incomes, counting a parent only if above the Low Income Threshold. General Care Equation: G = {A + [B x (C - D)]} x E, where D = highest Income Amount in the General Care Support Table (by number of children) not exceeding C, A = Base Support for that row, B = marginal percentage, E = parent's percentage share of family income (rounded to the nearest hundredth percent); round G to the nearest dollar. Low Income Equation (parent at or below the threshold H): L = 10% x parent's net income. Low Income Transition Equation (parent above H): T = (H x 10%) + [(I - H) x P], P = 50%/55%/60%/65%/70% for 1/2/3/4/5+ children; the parent's base support is the lower of G and T. Parental Time Offset (3.03): [Ao^2.5 x Bs - Bo^2.5 x As] / [Ao^2.5 + Bo^2.5], Ao/Bo = annual overnights with parent A/B, As/Bs = base support of A/B; negative result = A pays, positive = B pays. source
Income. 'Net income' means all income minus the deductions and adjustments permitted by the manual (2025 MCSF 2.01(A)); income includes wages, overtime, commissions, bonuses (Medicare wages box of the W-2), business, self-employment and rental earnings and other listed items (2.01(C)). Deductions include actual federal, state and local income taxes, FICA/Medicare, alimony paid to a third person, and an adjustment multiplier (83%/75%/68%/64%/60%) for additional children from other relationships (2.07, 2.08).
Parenting time. The parental time offset applies to every determination where the approximate annual overnights with each parent can be determined (no threshold): [Ao^2.5 x Bs - Bo^2.5 x As] / [Ao^2.5 + Bo^2.5]. It does not apply when a nonparent has custody; a change of at least 21 overnights (or one exceeding the modification threshold) allows a motion to modify (2025 MCSF 3.03).
Child care and health care. actual net child-care costs (after subsidies and credits) allocated by each parent's percentage share of family income; payer's share ordered as a monthly child care obligation (2025 MCSF 3.06) premiums for the children allocated between parents by income share; ordinary medical expense amount ($200 per child per year) apportioned by income share (2025 MCSF 3.04-3.05; 2025 MCSF-S 2.02) A support obligation = base support adjusted by the parental time offset + medical support (ordinary and additional medical expenses, health-care coverage premiums) + child care (2025 MCSF 3.01(A)).
Low incomes. The Low Income Threshold is $1,255.00 (2024 HHS poverty guideline) (2025 MCSF-S 2.01(A)). A parent at or below it pays 10% of net income and that income is excluded from family income for the other parent's calculation; a parent above it pays the lower of the General Care Equation and the Low Income Transition Equation (2025 MCSF 2.09, 3.02(C)-(D)).
When support ends. Support may continue after 18 while the child regularly attends high school full time with a reasonable expectation of graduating and lives full time with the recipient (or at an institution), but never after the child reaches 19 years and 6 months (MCL 552.605b(2)). source
The state also runs its own official child support calculator; use it, or the court's worksheet, for a filing.
Worth knowing in Michigan
- Michigan's guideline is the Michigan Child Support Formula manual plus its most current supplement, published by the SCAO Friend of the Court Bureau; the 2025 edition took effect January 1, 2025 (2025 MCSF 1.01). source
- The parenting time offset raises each parent's annual overnights to the power 2.5, so support falls gradually as overnights rise rather than at a threshold (2025 MCSF 3.03). source
- A friend of the court office must petition to modify when the recommended amount differs from the current order by more than 10% or $50 a month, whichever is greater (2025 MCSF 4.05). source
- Weekly amounts are converted to monthly by multiplying by 4.35 and biweekly by 2.175 (2025 MCSF 4.06(A)). source
- The 2025 supplement adjusts the General Care Support Table income levels using the February 2024 CPI-U Detroit from an April 2023 base (2025 MCSF-S 2.03(A)). source