Calculation is client-side, income figures are never transmitted or stored.
How Maryland Child Support Is Calculated
- Determine each parent's monthly adjusted actual income, then combine both for combined monthly adjusted actual income.
- Look up the basic child support obligation from the official Schedule of Basic Child Support Obligations for that combined income and number of children -- the schedule's own self-support reserve adjustment is already built into its lower-income rows.
- If neither parent has shared physical custody (92+ overnights/year for the parent with less time), each parent's share of the basic obligation plus childcare/health costs is the standard proration.
- If both parents have shared physical custody (92+ overnights each), a cross-formula applies instead: the basic obligation is multiplied by 1.5, then each parent's share is cross-multiplied by the OTHER parent's time share -- the difference is the support owed, paid by whichever parent's theoretical amount is larger.
- In the narrow 92-109 overnight band specifically, an additional graduated bonus (2%-10%, higher for fewer nights within that band) increases the paying parent's theoretical amount.
- The shared-custody result is capped at the sole-custody amount if that would be lower.
- Above $30,000/month combined income, courts use discretion rather than an automatic formula.
Maryland Child Support Worksheet Walkthrough
Example: combined adjusted actual income $5,000/month, 2 children, Parent A earns $3,000/mo (60% share), Parent B earns $2,000/mo (40% share) and has 100 overnights/year (in the narrow 92-109 bonus band).
- Basic child support obligation for $5,000 combined, 2 children: $1,356/month.
- Adjusted (x1.5) basic obligation for the shared-custody cross-formula: $2,034/month.
- Cross-multiplying each parent's income share and time share, plus the narrow-band bonus for Parent B's 100 overnights (99-102 night bracket, +6%), produces $292/month owed by Parent B -- below the $542/month sole-custody amount, so the shared-custody result applies.
How This Calculator Works — Formula & Constants
Source: Maryland General Assembly, Md. Code, Family Law § 12-204 · Calcul déterministe — no AI, no arbitrary estimate.
Constants used
| Constant | Value | Source |
|---|
Formula
base_obligation = schedule_lookup(combined_income, children)
share_B = parentB_income / combined_income
total_obligation = base_obligation + childcare_cost + health_insurance_cost
obligation_B = total_obligation × share_B
obligation_B = obligation_B × (1 - custody_credit(overnights))
Deterministic calculation based on Maryland's official guideline schedule table. Verify against Maryland's official calculator for a court-ready figure.
FAQ
How is child support calculated in Maryland?
Determine each parent's monthly adjusted actual income, then combine both for combined monthly adjusted actual income. Look up the basic child support obligation from the official Schedule of Basic Child Support Obligations for that combined income and number of children -- the schedule's own self-support reserve adjustment is already built into its lower-income rows. If neither parent has shared physical custody (92+ overnights/year for the parent with less time), each parent's share of the basic obligation plus childcare/health costs is the standard proration. If both parents have shared physical custody (92+ overnights each), a cross-formula applies instead: the basic obligation is multiplied by 1.5, then each parent's share is cross-multiplied by the OTHER parent's time share -- the difference is the support owed, paid by whichever parent's theoretical amount is larger. In the narrow 92-109 overnight band specifically, an additional graduated bonus (2%-10%, higher for fewer nights within that band) increases the paying parent's theoretical amount. The shared-custody result is capped at the sole-custody amount if that would be lower. Above $30,000/month combined income, courts use discretion rather than an automatic formula.
What is Maryland's narrow-band shared custody bonus?
When a parent with shared physical custody has between 92 and 109 overnights per year (25%-30% of the time), Maryland adds an EXTRA graduated bonus to that parent's theoretical obligation in the cross-formula -- 10% at 92-94 nights, stepping down to 2% at 106-109 nights. This is on top of the standard shared-custody cross-multiplication, and only applies in this specific narrow range.
Is Maryland's self-support reserve a separate calculation?
No -- unlike some states that compare two separate calculations, Maryland bakes the self-support reserve adjustment directly into the printed Schedule of Basic Child Support Obligations. Rows below roughly $1,650/month combined income (marked with an asterisk in the statute) already reflect the reduced, reserve-adjusted amount, so no extra step is needed beyond the standard schedule lookup.
What happens if combined income is above $30,000/month in Maryland?
Above $30,000/month in combined adjusted actual income, Maryland's schedule provides no further value. Courts use their discretion in setting the support amount (Md. Fam. Law § 12-204(d)) rather than extending the schedule with an automatic formula.
Methodology & Source
Formula model: income shares. Effective 2022-07-01, guideline version 2022-MD-v1, last reviewed 2026-07-13.
Official source: Maryland General Assembly, Md. Code, Family Law § 12-204 (Md. Code, Family Law § 12-204).
Above $30,000/month combined adjusted actual income, Maryland's schedule has no further value -- courts use discretion in setting support (Md. Fam. Law 12-204(d)) rather than an automatic formula. This calculator approximates the shared-custody formula's add-on cost split (each parent's own childcare/health costs credited separately) as a single combined figure, since it collects one childcare/health-insurance amount rather than a separate figure per parent.
Guideline figures transcribed from the primary source above and cross-checked against Maryland's official calculator/worksheet for multiple test scenarios — see our verification methodology.