Substantial presence test day count examples
What this page covers
Substantial presence test day count examples
This page walks through simple, numeric examples of how day counting works for the U.S. substantial presence test, so you can see how different travel patterns can affect your U.S. tax residency status.
Use these examples only as a high-level guide. They do not replace professional advice or the detailed IRS rules that may apply to your specific facts, visa status, exemptions, and tax years.
In brief
- Basic day-count formula
- For the substantial presence test, you generally add all U.S. days in the current year, plus 1/3 of your U.S. days in the prior year, plus 1/6 of your U.S. days from two years ago. If that weighted total is 183 days or more and you were in the U.S. at least 31 days in the current year, you usually meet the test.
- Example of meeting the test
- If you spent 140 days in the U.S. this year, 150 days last year, and 120 days two years ago, your total is 140 + 50 (1/3 of 150) + 20 (1/6 of 120) = 210 days. Because this is at least 183 and you were in the U.S. at least 31 days this year, you would generally meet the substantial presence test.
What to do
The substantial presence test is a U.S. tax residency test that looks at how many days you were physically present in the United States over a three-year period. To apply the basic rule, you first count all days you were in the U.S. in the current calendar year. Then you add 1/3 of the days you were in the U.S. in the immediately preceding year and 1/6 of the days you were in the U.S. in the year before that. If this weighted total is 183 days or more, and you were in the U.S. at least 31 days in the current year, you generally meet the substantial presence test.
Example 1 – clearly meets the test: Assume you were in the U.S. 160 days in 2026, 150 days in 2025, and 120 days in 2024. Your weighted total for 2026 is 160 (all 2026 days) + 50 (1/3 of 150) + 20 (1/6 of 120) = 230 days. Because 230 is above 183 and you were in the U.S. more than 31 days in 2026, you would generally be treated as a U.S. resident for tax purposes under the substantial presence test for 2026, unless an exception applies.
Example 2 – just below the threshold: Assume you were in the U.S. 110 days in 2026, 110 days in 2025, and 110 days in 2024. Your weighted total is 110 + 37 (1/3 of 110, rounded) + 18 (1/6 of 110, rounded) = 165 days. Because 165 is less than 183, you would not meet the substantial presence test for 2026 under the basic formula, even though you spent more than 31 days in the U.S. that year. Example 3 – impact of a heavier current year: Assume you were in the U.S. 200 days in 2026, 40 days in 2025, and 20 days in 2024. Your weighted total is 200 + 13 (1/3 of 40, rounded) + 3 (1/6 of 20, rounded) = 216 days. Even though your prior-year presence was relatively low, the high number of days in the current year pushes you over the 183-day threshold, so you would generally meet the substantial presence test for 2026.
What to keep in mind
The examples on this page show only the core day-counting mechanics of the substantial presence test. They assume that every day you are physically in the U.S. counts in full and ignore special categories of days that may be excluded under the tax rules. In real situations, days as a qualifying teacher, trainee, student, or certain foreign government–related individual may not count, and some medical-condition days can also be excluded if strict criteria are met.
Even if your weighted total is 183 days or more, you might still be able to avoid U.S. resident status in limited cases, such as by qualifying for a closer connection to a foreign country or applying a tie-breaker rule under an income tax treaty. These options have their own conditions, documentation requirements, and deadlines. Conversely, if you are close to the threshold, a few extra days in the U.S. can change your status, so tracking your travel precisely by calendar day is essential.
Because the substantial presence test interacts with other residency rules and exceptions, the simple numerical examples here should not be used as a final determination of your status. Your actual outcome can differ if you have visa-related exemptions, treaty protection, or unusual travel patterns. For important decisions, such as planning extended U.S. stays or filing your U.S. tax return, consider reviewing official IRS guidance and speaking with a qualified tax professional who can apply the rules to your specific facts and years.