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Immigration, Visa & Travel DocumentsGenerated accuracy model review: 2026-05-06
Tax Residency Substantial Presence Calculator accuracy and testing
This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.
Formula source
- Adjusted current-year days = current-year days - exempt current-year days. Weighted presence days = adjusted current-year days + first prior-year days / 3 + second prior-year days / 6. Planning status checks adjusted current-year days against the current-year minimum and weighted presence days against the weighted threshold.
Test cases
Default input regression check
Generated from the checked-in default inputs and calculate function.
Inputs
- Current-Year Days: 120 days
- First Prior-Year Days: 120 days
- Second Prior-Year Days: 120 days
- Exempt Current-Year Days: 0 days
- Minimum Current-Year Days: 31 days
- Weighted Threshold: 183 days
Expected outputs
- Weighted Presence Days: 180 days
- Adjusted Current-Year Days: 120 days
- Days Above/Below Weighted Threshold: -3 days
- Planning Status: Entered thresholds are not met
Known limitations
- This calculator does not apply IRS forms, treaty tie-breakers, closer-connection exceptions, visa-specific exempt-individual rules, filing obligations, state tax residency, or tax advice.
Assumptions
- The default formula uses a common substantial-presence-style weighting: current year + first prior year / 3 + second prior year / 6.
- Exempt days are user-entered and are not validated by the calculator.
- This calculator runs in your browser from the values you enter. It is a planning estimate only, not legal, tax, immigration, or official government advice.
Unit handling
- Current-Year Days accepts values in days.
- First Prior-Year Days accepts values in days.
- Second Prior-Year Days accepts values in days.
- Exempt Current-Year Days accepts values in days.
- Minimum Current-Year Days accepts values in days.
- Weighted Threshold accepts values in days.
- Weighted Presence Days is displayed in days.
- Adjusted Current-Year Days is displayed in days.
- Days Above/Below Weighted Threshold is displayed in days.
Rounding rules
- Number displays use up to 2 decimal places in the calculator UI.
- Input precision follows configured step values where provided.
Version history
1.0.0 - 2026-05-06
Generated accuracy and testing page from the current tax-residency-substantial-presence-calculator calculator definition.
Change log
2026-05-06
Published default regression test documentation and metadata fallbacks for Tax Residency Substantial Presence Calculator.
Calculator transparency
Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.