Calculation is client-side, income figures are never transmitted or stored.
How Michigan Child Support Is Calculated
- Determine each parent's net income (gross income minus taxes, mandatory retirement, and other allowable deductions).
- If a parent's net income is at or below the Low Income Threshold ($1,255/month), that parent's base support obligation is simply 10% of their income.
- Otherwise, combine both parents' net incomes into family income, look up the General Care Support Table bracket for that family income and number of children, and apply the General Care Equation: Base Support + (Marginal Percentage × amount over the bracket threshold), multiplied by that parent's income share.
- Apply the Parental Time Offset Equation using each parent's approximate annual overnights, which produces the final monthly transfer amount directly — a negative result means Parent A pays, positive means Parent B pays.
Michigan Child Support Worksheet Walkthrough
Example: Parent A net income $4,500/month (60% share), Parent B net income $3,000/month (40% share), 2 children, Parent A has 100 overnights/year, Parent B has 265.
- Family income: $7,500/month, bracket: $7,198.27 (2 children) — Base $2,095.42 + 20.20% × ($7,500−$7,198.27) = $2,156.32.
- Parent A's base obligation: $2,156.32 × 60% = $1,293.79.
- Parent B's base obligation: $2,156.32 × 40% = $862.53.
- Parental Time Offset: (100^2.5 × 862.53 − 265^2.5 × 1293.79) / (100^2.5 + 265^2.5) — a negative result, so Parent A pays the guideline amount.
How This Calculator Works — Formula & Constants
Source: Michigan Child Support Formula Manual (State Court Administrative Office) · Calcul déterministe — no AI, no arbitrary estimate.
Constants used
| Constant | Value | Source |
|---|---|---|
| Low Income Threshold | $1,255/mo | MCL 552.605 et seq.; 2025 MCSF §§3.02-3.03 |
| General Care Support Tables | 5 tables (1-5+ children), 6 income brackets each | MCL 552.605 et seq.; 2025 MCSF §§3.02-3.03 |
Formula
base(parent) = (parent_income ≤ 1255) ? parent_income × 10% :
(BaseSupport[bracket] + MarginalPct[bracket] × (family_income - BracketThreshold)) × parent_share
Ao, Bo = each parent's annual overnights
offset = (Ao^2.5 × Bs - Bo^2.5 × As) / (Ao^2.5 + Bo^2.5)
offset < 0 → Parent A pays |offset| · offset > 0 → Parent B pays offset
Deterministic calculation based on the Michigan Child Support Formula's General Care Equation and Parental Time Offset Equation (2025 MCSF §§3.02-3.03). Verify against Michigan's official calculator for a court-ready figure.
FAQ
How is child support calculated in Michigan?
Determine each parent's net income (gross income minus taxes, mandatory retirement, and other allowable deductions). If a parent's net income is at or below the Low Income Threshold ($1,255/month), that parent's base support obligation is simply 10% of their income. Otherwise, combine both parents' net incomes into family income, look up the General Care Support Table bracket for that family income and number of children, and apply the General Care Equation: Base Support + (Marginal Percentage × amount over the bracket threshold), multiplied by that parent's income share. Apply the Parental Time Offset Equation using each parent's approximate annual overnights, which produces the final monthly transfer amount directly — a negative result means Parent A pays, positive means Parent B pays.
How does Michigan's Parental Time Offset work?
See the guidelines section above.
What is Michigan's Low Income Threshold?
See the guidelines section above.
What counts as net income in Michigan?
See the guidelines section above.
Methodology & Source
Formula model: michigan formula. Effective 2025-01-01, guideline version 2025-MCSF-v1, last reviewed 2026-07-11.
Official source: Michigan Child Support Formula Manual (State Court Administrative Office) (MCL 552.605 et seq.; 2025 MCSF §§3.02-3.03).
Courts may deviate from the guideline amount for documented reasons (Section 1.04) — this calculator shows the presumptive guideline amount only, not a court order. Simplification: this calculator does not model the per-parent family-income exclusion nuance (MCSF 2.09(B)) when one parent's income is near the Low Income Threshold — consult Michigan's official Support Estimator for edge cases near $1,255/month.
Guideline figures transcribed from the primary source above and cross-checked against Michigan's official calculator/worksheet for multiple test scenarios — see our verification methodology.