Calculation is client-side, income figures are never transmitted or stored.
How Pennsylvania Child Support Is Calculated
- Determine each parent's monthly net income, then combine both for combined monthly net income.
- Look up the basic obligation two ways: (a) using the paying parent's own individual net income alone, and (b) using combined income multiplied by that parent's income share — the LESSER of the two applies. This mirrors the schedule's Self-Support Reserve (SSR) protection.
- If the paying parent's net income is at or below the SSR ($1,255/month), courts have full discretion rather than an automatic formula result.
- If the paying parent has 146 or more overnights per year (40%+ shared physical custody), a separate shared-custody adjustment formula applies (Pa.R.Civ.P. 1910.16-4(a)(1)(Part D)) — not computed by this calculator.
- Add each parent's pro rata share of childcare costs and health insurance premiums.
- Above $30,000/month combined net income, courts use the high-income formula (Pa.R.Civ.P. 1910.16-3.1) rather than the schedule.
Pennsylvania Child Support Worksheet Walkthrough
Example: combined net income $5,000/month, 2 children, Parent A earns $3,000/mo (60% share), Parent B earns $2,000/mo (40% share) and is the noncustodial parent with under 146 overnights/year.
- Individual-income lookup for Parent B alone ($2,000/mo, 2 children): $678/month.
- Combined-income lookup at $5,000/mo, 2 children: $1,629/month; Parent B's 40% share: $652/month.
- Pennsylvania uses the LESSER of the two: $652/month guideline child support paid by Parent B.
How This Calculator Works — Formula & Constants
Source: Pennsylvania Rules of Civil Procedure (Pa.R.Civ.P. 1910.16-3) · Calcul déterministe — no AI, no arbitrary estimate.
Constants used
| Constant | Value | Source |
|---|---|---|
| Overnights threshold | 146 nights/yr | Pa.R.Civ.P. 1910.16-1 through 1910.16-7 |
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 Pennsylvania's official guideline schedule table. Verify against Pennsylvania's official calculator for a court-ready figure.
FAQ
How is child support calculated in Pennsylvania?
Determine each parent's monthly net income, then combine both for combined monthly net income. Look up the basic obligation two ways: (a) using the paying parent's own individual net income alone, and (b) using combined income multiplied by that parent's income share — the LESSER of the two applies. This mirrors the schedule's Self-Support Reserve (SSR) protection. If the paying parent's net income is at or below the SSR ($1,255/month), courts have full discretion rather than an automatic formula result. If the paying parent has 146 or more overnights per year (40%+ shared physical custody), a separate shared-custody adjustment formula applies (Pa.R.Civ.P. 1910.16-4(a)(1)(Part D)) — not computed by this calculator. Add each parent's pro rata share of childcare costs and health insurance premiums. Above $30,000/month combined net income, courts use the high-income formula (Pa.R.Civ.P. 1910.16-3.1) rather than the schedule.
Why does Pennsylvania calculate child support two different ways and use the lower amount?
Pennsylvania's rule (Pa.R.Civ.P. 1910.16-2(e)(1)(ii)) requires comparing the obligation calculated from the paying parent's own income alone against the obligation calculated from combined income and that parent's income share, then using whichever is LOWER. This protects lower-income paying parents and is what produces the Self-Support Reserve built into the schedule's low end.
What is Pennsylvania's Self-Support Reserve?
The Self-Support Reserve (SSR) is $1,255/month as of the 2026 schedule — the minimum monthly net income the law reserves to the paying parent to meet basic needs. If the paying parent's net income is at or below the SSR, courts have full discretion to set support after considering actual financial resources and living expenses, rather than applying the schedule automatically.
Does shared custody reduce child support in Pennsylvania?
Yes, but only past a specific threshold: if the paying parent has 40% or more of the annual overnights (146+ nights), a separate shared-custody adjustment formula under Pa.R.Civ.P. 1910.16-4(a)(1)(Part D) applies instead of the basic calculation. Below that threshold, the standard formula applies regardless of how time is actually split.
What happens if combined income is above $30,000/month in Pennsylvania?
Above $30,000/month in combined net income, Pennsylvania's schedule doesn't provide a table value. Courts instead use the high-income formula under Pa.R.Civ.P. 1910.16-3.1 rather than extending the basic schedule.
Methodology & Source
Formula model: income shares. Effective 2026-01-01, guideline version 2026-PA-v1, last reviewed 2026-07-12.
Official source: Pennsylvania Rules of Civil Procedure (Pa.R.Civ.P. 1910.16-3) (Pa.R.Civ.P. 1910.16-1 through 1910.16-7).
Above $30,000/month combined net income, Pennsylvania's schedule has no table value — courts use the high-income formula under Pa.R.Civ.P. 1910.16-3.1 instead. This calculator does not model the shared-custody adjustment (Pa.R.Civ.P. 1910.16-4(c), triggered at 146+ overnights/year for the paying parent) or spousal support/APL interactions.
Guideline figures transcribed from the primary source above and cross-checked against Pennsylvania's official calculator/worksheet for multiple test scenarios — see our verification methodology.