How the test works
You meet the test for a calendar year if you were physically in the US for at least 31 days that year and at least 183 days over three years. All days of the current year count, one third of the days of the previous year, and one sixth of the days of the year before that.
For example, 120 days in each of the three years gives 120 + 40 + 20 = 180 weighted days, so the test is not met.
Some days do not count: regular commuting from Canada or Mexico, transit of less than 24 hours, work as a crew member of a foreign vessel, days when a medical condition that arose in the US prevented you from leaving, and days as an exempt individual, such as many students and teachers on F, J, M or Q visas. The calculator does not subtract these days, so enter only the days that count.
FAQ
Do partial days count?
Yes. Generally, any part of a day in the US counts as a full day, except for the excluded days listed above.
Does a green card holder need this test?
No. A lawful permanent resident is generally a US tax resident under the green card test, whatever the number of days.
What if I meet the test but live abroad?
If you spent fewer than 183 days in the US this year and have a tax home and closer connection to another country, you may be treated as a nonresident. A tax treaty can also change the result.
How are fractions handled?
The IRS examples use whole numbers. This calculator keeps fractions without rounding down, which is the more cautious reading near the threshold.
This calculator gives a general estimate and is not tax or legal advice. Check your situation with a qualified tax adviser or on irs.gov.