Local Income Tax Split

Calculate local income tax across caller-supplied jurisdictions and rates.

Description

Local-income-tax aggregation pairs each wage amount with its jurisdictional rate.

Local-income-tax aggregation pairs each wage amount with its jurisdictional rate. Dividing aggregate tax by aggregate wages gives a weighted effective rate.^[1]

Calculate local income tax across caller-supplied jurisdictions and rates.

When to use Local Income Tax Split

Use this tool to calculate local income tax across caller-supplied jurisdictions and rates.

Choose the specific arithmetic or checklist scenario and establish its input amounts, dates, rates and criteria from the applicable records. Keep currencies, periods and jurisdictions consistent; review the tool-specific assumptions before interpreting the result.

How to use Local Income Tax Split and understand its results

Choose the specific arithmetic or checklist scenario and establish its input amounts, dates, rates and criteria from the applicable records. Keep currencies, periods and jurisdictions consistent; review the tool-specific assumptions before interpreting the result.
Enter jurisdictionWages, localTaxRatesPercent using the field table and calculation rules, then run the tool.
Read localTaxes, totalLocalTax, effectiveRatePercent. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
jurisdictionWages	Wages by local jurisdiction	list of number	Required
localTaxRatesPercent	Local rates by jurisdiction (%)	list of number	Required

Enter aligned nonempty nonnegative wage/rate lists. Calculate each jurisdiction’s modeled tax and aggregate wages. Return per-jurisdiction tax amounts, total local tax and weighted effective percentage.

tax_i=wages_i×rate_i/100; effective%=100Σtax/Σwages, or 0 when total wages=0

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
localTaxes	Tax by jurisdiction	list of number
totalLocalTax	Total local income tax	number; minimum: 0
effectiveRatePercent	Effective local tax rate (%)	number; minimum: 0

json

{
  "input": {
    "jurisdictionWages": [
      1000,
      2000
    ],
    "localTaxRatesPercent": [
      1,
      2
    ]
  },
  "output": {
    "localTaxes": [
      10,
      40
    ],
    "totalLocalTax": 50,
    "effectiveRatePercent": 1.6666666666666667
  }
}

Limitations and assumptions

No credit, reciprocity, residence allocation or jurisdiction choice is inferred. Preserve pair order and a common currency/time basis.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Remote-Work Tax Overlap: Estimate overlapping remote-work state taxes using caller-supplied rates and creditability. For a complementary task, use Duty-Day Income Allocation: Allocate compensation by caller-supplied jurisdiction and total duty days.

References

Local Income Tax Split — tool.io

Similar or alternative tools

Remote-Work Tax Overlap
Estimate overlapping remote-work state taxes using caller-supplied rates and creditability.
Duty-Day Income Allocation
Allocate compensation by caller-supplied jurisdiction and total duty days.