Calculator Form
Formula Used
The calculator first removes excluded days from physical presence days.
Countable 2021 days = 2021 presence days − 2021 excluded days.
Countable 2020 days = 2020 presence days − 2020 excluded days.
Countable 2019 days = 2019 presence days − 2019 excluded days.
Weighted total = 2021 countable days + (2020 countable days ÷ 3) + (2019 countable days ÷ 6).
The test is met when 2021 countable days are at least 31 and the weighted total is at least 183.
How to Use This Calculator
Enter total physical presence days for 2021, 2020, and 2019.
Enter excluded days for each year. These may include exempt individual days or other days that do not count.
Select the closer connection and green card options when they apply.
Press calculate. The result appears above the form and below the header.
Use the CSV or PDF button to keep a copy of the calculation.
Example Data Table
| Year | Physical Days | Excluded Days | Countable Days | Weight | Weighted Days |
|---|---|---|---|---|---|
| 2021 | 150 | 10 | 140 | 1 | 140.00 |
| 2020 | 120 | 0 | 120 | 1/3 | 40.00 |
| 2019 | 90 | 0 | 90 | 1/6 | 15.00 |
| Total weighted days | 195.00 | ||||
Overview
The substantial presence test is a day counting method. It helps estimate US tax residency for a calendar year. This calculator focuses on 2021. It uses countable days from 2021, 2020, and 2019. Each year receives a different weight. The result shows whether the two main thresholds are met.
Why the 2021 Test Matters
A person can be treated as a resident for tax purposes by physical presence. The test does not only look at 2021. It also uses part of the two earlier years. That makes the result statistical and historical. A small change in excluded days can change the final status. Students, teachers, trainees, diplomats, crew members, and medical visitors may have days that are not counted. Those exclusions must be entered carefully.
What the Calculator Measures
Enter total days physically present for each year. Then enter excluded days for the same year. The calculator subtracts exclusions from presence. It then applies the 2021 weight, the 2020 one-third weight, and the 2019 one-sixth weight. You also see deficits, surplus days, and closer connection notes. These details help explain the result instead of giving only one label.
Practical Interpretation
A passing result means the mathematical presence test is met. It does not always end the review. Treaty rules, green card status, exempt individual claims, and closer connection relief may still matter. A failing result means one or both numerical thresholds were not reached. The table helps show which threshold failed.
Record Keeping Tips
Keep travel logs, passport pages, I-94 records, school records, work calendars, and medical documents. Save the exported CSV or PDF with your worksheet. Review each excluded day before filing. Do not estimate when exact dates are available. A careful record protects the calculation and makes later review easier.
Using the Result
Use the result as a planning worksheet. It is not a tax opinion. For unusual cases, compare the output with official guidance or speak with a qualified tax adviser.
Common Data Checks
Check leap year limits for 2020. Check that excluded days never exceed physical days. Review transit days separately. Mark only days allowed by the rules. Keep one worksheet per tax year. This avoids mixing 2021 facts with later travel patterns later. Securely.
FAQs
What is the substantial presence test for 2021?
It is a day count test used to estimate whether physical presence in the United States creates resident status for tax purposes during 2021.
Which years are used in this calculator?
The calculator uses 2021, 2020, and 2019. It counts all eligible 2021 days, one-third of 2020 days, and one-sixth of 2019 days.
What are excluded days?
Excluded days are days that should not be counted under the rules. Examples may include certain exempt individual days, medical condition days, or special travel days.
Does a passing result always mean resident status?
No. The calculator only checks the mathematical day count. Green card rules, treaty claims, closer connection relief, and special facts may affect the final answer.
Why is 2020 divided by three?
The substantial presence formula gives the first prior year a one-third weight. For a 2021 test, the first prior year is 2020.
Why is 2019 divided by six?
The second prior year receives a one-sixth weight. For a 2021 calculation, 2019 is the second prior year.
What happens if 2021 days are below 31?
The test fails even when the weighted total reaches 183. The current year must have at least 31 countable days.
Can I download the result?
Yes. After calculation, use the CSV or PDF buttons. They export the latest result stored during your session.