Substantial Presence Test Calculator
Count your US days over three years to see whether the IRS treats you as a US tax resident — and, if you're a Canadian snowbird, whether you can file Form 8840 to stay a nonresident.
Enter your days to see your result
Count only days you were physically present in the US. Exempt days (certain visa holders, days you commuted from Canada, days in transit, medical-condition days) generally do not count.
Educational estimate of the mechanical day-count only. It does not account for exempt individuals, dual-status years, or treaty tie-breakers. Confirm your status with a cross-border CPA.
How the test works
The IRS Substantial Presence Test has two parts, and you must meet both to be a US tax resident for the year:
- The 31-day rule — at least 31 days of US presence in the current year.
- The 183-day weighted rule — all your days this year, plus ⅓ of last year's days, plus ⅙of the year-before's days, totalling 183 or more.
The weighting is why a Canadian who spends a few winter months in the US each year can quietly cross the line: three consecutive winters of ~120 days average out above 183 on the weighted math.
The snowbird escape hatch is Form 8840. If you meet the test but were present fewer than 183 actual days this year, kept a home base in Canada, and have a closer connection to Canada, you can file the Closer Connection Exception (Form 8840) and remain a nonresident. But if your actual days reach 183 in a single year, that door closes — only the Canada-US treaty tie-breaker remains.
Frequently Asked Questions
What is the Substantial Presence Test?
It is the IRS day-count test (IRC §7701(b)(3)) that decides whether a non-US-citizen is a US tax resident for the year. You meet it if you were physically present in the US at least 31 days in the current year AND your weighted total over the last three years is 183 days or more. Meeting it means the US treats you as a resident taxed on worldwide income — unless an exception or treaty applies.
How is the weighted 183-day total calculated?
Add all your US days this year, plus one-third of your days last year, plus one-sixth of your days the year before. If that total is 183 or more (and you had at least 31 days this year), you meet the test. This calculator does the math for you.
I'm a Canadian snowbird — how do I avoid being taxed as a US resident?
The Closer Connection Exception. Even if you meet the Substantial Presence Test, you can still be treated as a nonresident if you were present fewer than 183 days this calendar year, you kept a tax home in Canada, you have a closer connection to Canada than to the US, and you timely file Form 8840 (Closer Connection Exception Statement for Aliens). Many Canadian snowbirds file Form 8840 every year for exactly this reason.
What if I was in the US 183 or more days this year?
Then the Closer Connection Exception is not available to you, no matter how strong your Canadian ties are — that rule turns strictly on your actual (unweighted) days in the current year. Your only remaining route to nonresident treatment would be the Canada-US tax treaty residency tie-breaker, which is a more involved position. Speak to a cross-border CPA.
Which days don't count toward the test?
Days you are an 'exempt individual' (certain F, J, M, and Q visa holders, and others), days you regularly commute to work in the US from a residence in Canada or Mexico, days you are in the US for less than 24 hours in transit, days you cannot leave because of a medical condition that arose while in the US, and days as a crew member of a foreign vessel. Only count days of genuine physical presence that are not exempt.
Does meeting the test mean I owe US tax on my Canadian rental income?
If you are treated as a US resident for the year, the US taxes your worldwide income — including Canadian rental income — for that year. But the Closer Connection Exception (Form 8840) or the treaty tie-breaker can preserve your nonresident status, in which case the US generally taxes only your US-source income. Because the stakes are high, confirm your status with a cross-border CPA before filing.
⚠️ Important Disclaimer
This content is for informational purposes only and does not constitute legal, tax, accounting, or financial advice. Tax laws change frequently — always verify with the CRA and IRS or consult a qualified cross-border tax accountant before making decisions.
BorderBird is a rental-management and record-keeping tool. It is not an accountant and does not provide accounting, tax, or legal advice.
Rates and rules reviewed against IRS guidance and current for the 2026 tax year — last reviewed August 2026. Tax rules change; confirm against the source before filing.
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