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Substantial Presence Test Calculator for Canadian Snowbirds
Count your US days the way the IRS does, then see whether you may need Form 8840 to stay a nonresident. Built by Gurleen Kaur, CPA licensed in British Columbia and Washington State.
Quick answer
How does the IRS substantial presence test work?
Under the IRS: Substantial presence test, you meet the test if you were physically present in the US at least 31 days in the current year and 183 days over three years, counting all days this year, one-third of last year's days and one-sixth of the days two years ago. Meeting it makes you a US resident for tax purposes unless an exception applies. A Canadian who was present fewer than 183 days this year, kept a tax home in Canada and had a closer connection to Canada can generally claim the closer connection exception by filing Form 8840 on time.
Count your days
Enter the days you were physically in the US in each year. Your answers stay in your browser.
Form 8840 basics
- Conditions: fewer than 183 days in the US this year, a tax home in Canada for the whole year, a closer connection to Canada than to the US, and no green card application or steps toward one (IRS).
- Filing: attach Form 8840 to your US return if you file one; otherwise send it to the IRS by the due date for filing the return (IRS).
- For a nonresident with no US wages, that due date is June 15 for a calendar year (Form 1040-NR instructions).
- Late filing can cost you the exception unless you show clear and convincing evidence of reasonable steps to comply.
Days that do not count
- Days you regularly commute to work in the US from a home in Canada
- Days in the US for less than 24 hours while in transit between two places outside the US
- Days you could not leave because of a medical condition that arose in the US
- Days as an exempt individual, such as certain students and teachers
Source: IRS: Substantial presence test. Details are in IRS Publication 519, U.S. Tax Guide for Aliens.
Common questions
How many days can a Canadian snowbird spend in the US?
The weighted formula is what matters. The IRS example shows that 120 days in each of three years totals 180 weighted days (120 + 40 + 20), just under 183. At about 122 days every year the total reaches 183, so regular snowbirds are often close to the line and Form 8840 becomes important.
What is Form 8840?
The Closer Connection Exception Statement for Aliens. It lets someone who meets the substantial presence test, but was in the US fewer than 183 days this year and has closer ties to Canada, be treated as a nonresident.
When is Form 8840 due?
With your US return if you file one. If you do not have to file, send it by the due date for filing the return, which is June 15 for a nonresident without US wages.
What if I was in the US 183 days or more this year?
The Form 8840 exception is not available. A treaty tie-breaker position under the Canada-US treaty may still apply, which needs a review and usually a disclosure.
Is my data stored?
No. The calculator runs entirely in your browser and does not send your numbers anywhere.
Does a green card change this?
Yes. A green card holder is generally a US resident under the green card test regardless of days, and taking steps toward a green card makes the closer connection exception unavailable.
Sources
Every rule and figure on this page links to the IRS, CRA or other official source it comes from. Amounts change; we re-check them before each engagement.
- IRS: Substantial presence test
- IRS: Closer connection exception to the substantial presence test
- IRS: About Form 8840
- IRS: Instructions for Form 1040-NR
- IRS Publication 519, U.S. Tax Guide for Aliens
Gurleen Kaur, CPA licensed in British Columbia and Washington State. Last updated October 21, 2026. This page is general information, not tax or legal advice for your situation.
Related guides: Snowbird tax and Form 8840, Treaty residence, US estate tax for Canadians.
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