About this Tax Residency Substantial Presence Calculator
The U.S. substantial presence test is often summarized with a weighted three-year day formula, but exceptions, visas, treaties, exempt individuals, and closer-connection rules can change the outcome. Use this tool only to organize a planning estimate before tax or legal review.
Who this calculator is for
- Visitors organizing current and prior-year U.S. day counts.
- Taxpayers preparing questions for a CPA, enrolled agent, attorney, or school office.
- Advisors building a quick planning scenario from client-entered day totals.
When to use it
- Estimate whether a weighted day count crosses an editable threshold.
- Model exempt current-year days before discussing documentation.
- Compare the current-year minimum-day rule with the weighted total.
How to use this calculator
- Enter days physically present in the current year and two prior years.
- Enter exempt current-year days only if you have a rule-based reason to model them.
- Adjust the current-year minimum and weighted threshold if you are modeling a nonstandard checklist.
- Review the planning status with a qualified tax advisor before making filing decisions.
Key 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.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
Inputs explained
Current-year days
Physical-presence days in the year being evaluated before any exempt-day adjustment.
First prior-year days
Days from the immediately preceding year, weighted at one-third in the default model.
Second prior-year days
Days from two years before the current year, weighted at one-sixth in the default model.
Exempt current-year days
Current-year days you choose to exclude for planning because you believe an exception may apply.
Understanding your results
Example scenarios
Weighted count example
120 current-year days, 120 first prior-year days, and 120 second prior-year days produce 120 + 40 + 20 = 180 weighted days before exempt-day adjustments.
Exempt-day scenario
If 20 current-year days are entered as exempt, the model subtracts them before applying the current-year and weighted threshold checks.
Key Features
- Instant Calculation
- Private & Secure
- Mobile Optimized
Things to Keep in Mind
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.
Tips & Best Practices
- Keep a dated travel log and compare it with official arrival/departure records.
- Discuss student, teacher, medical, professional athlete, treaty, and closer-connection exceptions with a qualified tax professional.
- Do not use this estimate alone to choose a tax filing position.