183-day calculator
The most common tax-residency tripwire in the world is half a year plus one day. Enter your stays and see where you stand against 183 — and when you would cross it at this year's pace.
Every calendar day counts, including arrival and departure days. Add only the days you were present — days abroad do not offset.
- What this number means
- 183 days is half a year plus one — the bright line in the UK Statutory Residence Test, Canada's sojourner rule, and US state statutory-residency tests. India's basic test uses 182 days, and tax years differ (India: April–March; UK: April 5). This calculator does calendar-year arithmetic only; it does not decide your residency.
- Days remaining
- 183 days before the threshold.
Stays are saved in this browser only (localStorage) — nothing is sent anywhere. Clearing site data removes them.
The 183-day rule, jurisdiction by jurisdiction
Day-count tests share a skeleton — presence minus a threshold — but every jurisdiction bolts different conditions onto it. The counting engine above is generic on purpose; the caveats below are where the real answers live.
United Kingdom
Automatic UK residence under the Statutory Residence Test: 183 or more days in the UK in the tax year (ending April 5) makes you resident, full stop — no ties needed. Below 183, the sufficiency factors decide. Days count when you are in the UK at midnight. HMRC RDR3 guidance.
Canada
Sojourning in Canada 183 days or more in a calendar year makes you a deemed resident (Income Tax Act, s. 250(1)(a)) — the CRA reads "sojourn" broadly. Tax treaties with your home country usually override the deeming. CRA Folio S5-F1-C1.
India
The basic test is 182 days or more in the financial year (April to March), with shorter 60-day triggers when combined with prior-year presence, and a special 245-day rule for Indian citizens or persons of Indian origin visiting on foreign passports. Income-tax Act, s. 6.
US states
About half the US states keep a statutory-residency test — 183+ days of presence plus a permanent place of abode. New York's is the most aggressively audited, counting every day in any part of the year (not just to date). See our guides for New York, California, and Florida — the US federal test is a different animal entirely (substantial presence test).
Official sources
Rule summaries reviewed for 2026 — statutes change; verify against the linked official pages.
Frequently asked questions
Why 183 days?
183 days is half a year plus one — the point at which you have been present for the majority of a year. Legislatures use it as a bright line because it needs no judgement: count the days, compare the number. The UK Statutory Residence Test, Canada's sojourner rule, and US state statutory-residency tests all use 183 or a close variant.
Is the 183-day rule the same in every country?
No — the number is common but the surrounding law is not. The UK counts the tax year ending April 5 and stacks tie-breakers on top. Canada counts sojourn days in the calendar year but lets tax treaties override. India's basic test is 182 days over the April-to-March financial year, with shorter triggers for seafarers and crew. US states like New York count all 365 days and combine the count with domicile. Use this calculator for the arithmetic, then read the jurisdiction's own rules.
Do arrival and departure days count as full days?
Almost always yes — most statutes count any day with physical presence at any time, even a few hours (the US substantial presence test states this explicitly, and others follow). This calculator counts both the first and last day of every stay.
Can a tax treaty save me if I cross 183 days?
Often, yes. Treaties contain tie-breaker tests (permanent home, centre of vital interests, habitual abode, nationality) that can assign you to the other country even after you crossed the domestic threshold. But you generally must claim it — the counting comes first.
Does this calculator decide my tax residency?
No. It counts days and compares them to 183 — nothing more. Residency determinations add visa status, treaty positions, domicile, and purpose-of-stay tests on top of the raw count. Treat the output as a tripwire, not a verdict.
Count every jurisdiction at once
The Day31 app tracks your days in every country, US state, and Canadian province at the same time — with alerts before a threshold, not after. Offline and private, on your device.