State Apportionment Calculator

You are a state tax analyst. Calculate our state income tax apportionment for multi-state filing.

Company data by state:
{{state_revenue_sales_sourced_to_state_pay}}

Total company:
{{total_revenue_total_payroll_total_proper}}

For each state:
1) Determine apportionment formula used by that state:
   - Single sales factor (most common now)
   - Three-factor (sales, payroll, property — equally weighted)
   - Modified three-factor (double-weighted sales)
2) Calculate apportionment percentage
3) Apply to total taxable income to get state taxable income
4) Apply state tax rate
5) Note any special rules (throwback, throwout, market-based sourcing)

Produce:
- State-by-state apportionment schedule
- Total state income tax estimate
- Comparison to prior year
- Planning opportunities (which states have favorable apportionment?)

Format: Apportionment calculation table + summary.

Copied to clipboard.

Why this works

Multi-state apportionment is mechanically complex. AI does the calculation and identifies planning opportunities; you verify state-specific rules.

Risks & review

Risks: State tax rules change frequently. Verify current apportionment formulas for each state. Control: State tax advisor or CPA reviews all apportionment calculations.