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US N-400 Continuous Residence Calculator

Check your continuous-residence and physical-presence status for N-400 naturalization: flags trips that risk or break continuity and computes required presence days.

Counting convention: Absence days use the 'both travel days count as presence' convention (day of departure and day of return both count as days in the US). A single trip of 180 days up to just under 365 days creates a REBUTTABLE presumption that you broke continuous residence — USCIS may still accept it if you can show you did not abandon US residence (kept a home, job, family, filed taxes as a resident). A single trip of 365 days or more breaks continuous residence AUTOMATICALLY, with no rebuttal, and restarts your qualifying period from your return date. The physical-presence target shown is calculated as exactly half of your real (leap-year-accurate) qualifying-period day count, matching INA 316(a)'s 'at least half' standard — not a fixed estimate like '913 days'.
Trips abroad
Rule verified 2026-08 against USCIS "Continuous Residence and Physical Presence Requirements for Naturalization" policy guidance, uscis.gov; INA Section 316(a) — always confirm against the current official source before applying. Trip length thresholds (6 months, 1 year) and the 'at least half the period' physical-presence standard come directly from INA 316(a) and USCIS's own guidance page.

How to Use the US N-400 Continuous Residence Calculator

  1. Pick your eligibility route — the general 5-year permanent-residence route, or the 3-year married-to-a-US-citizen route.
  2. Enter the date you became a lawful permanent resident (your green card date) and your planned N-400 filing date (or leave it as today).
  3. Add a row for every trip outside the United States — departure and return date.
  4. Click Calculate. The tool checks continuous residence (has any trip broken or put your continuity at risk?) and physical presence (have you accumulated enough actual days in the US?) separately, because USCIS treats them as two distinct requirements.

Everything runs as plain JavaScript in your browser tab — nothing you enter is uploaded or stored.

Two Separate Requirements, Explained

Naturalization under the general provision (INA 316(a)) requires two things that are often confused for one:

  1. Continuous residence — you must not have interrupted your residence in the US with a long trip abroad. A single trip of 6 months (180 days) up to just under 1 year creates a rebuttable presumption that you broke continuous residence — USCIS may still accept your application if you can show strong ties (home, job, family, taxes filed as a resident) that prove you didn't abandon US residence during the trip. A single trip of 1 year (365 days) or more breaks continuous residence automatically, with no way to rebut it — your required residency period restarts entirely from the date you returned.
  2. Physical presence — regardless of whether any single trip broke continuity, every day you spend abroad still counts against a separate running total. You must be physically present in the US for at least half of your required residency period (30 months out of 5 years on the general route, or 18 months out of 3 years on the married-to-a-citizen route).

This tool computes the physical-presence target as an exact half of your real qualifying-period day count — leap-year accurate — rather than a rough estimate like "913 days," which is only an approximation of half of ~1,826 days and can be off by a day or two depending on which years are involved.

Counting Convention

Absence days use the "both travel days count as presence" convention: the day you leave the US and the day you return both count as days in the US; only the full calendar days strictly between them count as absence — the same days that also erode your physical-presence total.

Worked example: You became a permanent resident on 6 August 2021 (5-year route) and plan to file on 6 August 2026. Your qualifying window is exactly 1,826 days, so you need at least 913 presence days. A single 204-day trip during that window (roughly 6.7 months) falls in the 180–364-day "caution" band — it doesn't automatically break continuity, but USCIS could scrutinize it, and every one of those 204 days still counts against your physical-presence total.

What Breaks or Risks Your Eligibility

  • Any single trip of 365 days or more — automatic break, clock restarts from your return date.
  • Any single trip of 180–364 days — flagged as a caution: rebuttable, but only with evidence you maintained US ties throughout.
  • Falling short of the "at least half" physical-presence total, even if no individual trip was long enough to threaten continuity on its own — lots of medium-length trips can add up.

Frequently Asked Questions

Does this account for N-470 exceptions? No — approved extended absences for certain employment (e.g. with the US government, certain religious or research organizations) can preserve continuous residence beyond what's modeled here. If you have an approved N-470, treat a "reset" flag as inapplicable to your case.

Does this check the state/USCIS-district residency requirement? No — N-400 also requires 3 months of residency in the state or USCIS district where you file, which this tool does not check.

What if I have a mix of caution-band and short trips? Each caution-band trip is flagged individually; passing the physical-presence and elapsed-time checks doesn't guarantee USCIS won't still ask about a caution-band trip specifically.

Is this official USCIS guidance? No. This is an independent, browser-only estimate based on INA 316(a) and USCIS's own published policy guidance. Always confirm your specific case with an immigration attorney or USCIS before filing.

Is my data stored anywhere? No. The check runs entirely in your browser; nothing is transmitted to a server.

A free browser tool by Toolzer Hub. It runs on your device; files you add are not uploaded. More free tools