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FREE U.S. TAX-RESIDENCY TOOL

Substantial presence test calculator

Calculate the IRS weighted three-year day total and check the two numerical thresholds used in the substantial presence test. The result is a preliminary organizer, not a tax-residency determination.

No sign-upDay counts stay in your browserU.S. federal tax only

WEIGHTED DAY COUNTER

Check the 31-day and weighted 183-day thresholds

Enter countable U.S. days for the year being tested and the two prior years. Use travel records rather than estimates. Do not enter passport numbers, visa numbers, tax IDs, or documents.

Private by design: the calculation happens in this browser. Day counts are not included in analytics events or saved by this tool.

Enter countable days, not automatically every travel day.

Certain transit, commuter, medical-condition, student, teacher, trainee, government-related, and athlete days may be excluded. Review the IRS rules before using the result.

Choose the tax year and enter countable U.S. days
tax year

The three day-count fields below will use this year and the two preceding calendar years.

days

The IRS requires at least 31 countable days in 2026.

days

One-third of the 2025 days entered is included in the weighted total.

days

One-sixth of the 2024 days entered is included in the weighted total.

A green card, treaty position, closer-connection exception, first-year choice, residency start or end date, or other rule can change the filing result.

THE GENERAL IRS FORMULA

Two numerical requirements must be met

Current-year minimum

At least 31 countable days of physical presence in the United States during the current calendar year.

Weighted three-year minimum

At least 183 days after counting all current-year days, one-third of first-prior-year days, and one-sixth of second-prior-year days.

Exceptions and other tests

Excluded days, the closer-connection exception, treaty rules, green-card status, elections, and residency starting or ending dates can change the result.

Read the substantial presence test guide

Explore foreign-national U.S. tax preparation

IMPORTANT LIMITS

What the calculator does not determine

The tool applies only the two general numerical thresholds to the day counts entered. It does not prepare a return or decide a final U.S. tax-residency or immigration result.

  • Whether a particular day is countable or excluded under the IRS rules
  • Green-card-test status, treaty residence, or a closer-connection exception
  • Resident, nonresident, or dual-status filing dates and elections
  • Forms 1040, 1040-NR, 8840, 8843, 8833, or other filing requirements
  • State tax residency, foreign-country tax, immigration status, or visa rights
  • Tax due, withholding, estimated payments, information returns, or penalties

PRIMARY IRS GUIDANCE

Sources and review date

General rules and links reviewed August 2, 2026. The current IRS instructions and the taxpayer's complete facts control.