US Tax Residency TestUS tax residency: the substantial presence test
Enter your days in the United States for three years. IRS rules read on 13 November 2026. Nothing is stored.
How the count works
Add all the days of this year, one third of last year’s days and one sixth of the days the year before. You also need at least 31 days this year. A total of 183 or more means you meet the test.
Common questions
What is the substantial presence test?
The IRS treats you as a US resident for tax if you are present in the United States on at least 31 days in the current year and at least 183 days in the three-year period, counting all days this year, one third of last year’s days and one sixth of the days the year before.
Does the IRS’s own example agree?
Yes. 120 days in each of 2023, 2024 and 2025 gives 120 + 40 + 20 = 180 days, below 183, so the person is not a resident under the test for 2025. The calculator opens on those figures.
Do all days count?
No. Days as an exempt individual and some other days do not count; see the page on days that do not count.
Source
- Internal Revenue Service, "Substantial presence test", irs.gov, read on 13 November 2026.
Rules read on 13 November 2026 from the IRS website. They may have changed since. This site is independent, not connected with the IRS, and gives arithmetic, not tax advice.