Pick a jurisdiction, then enter your days and ties. Each follows the common local test: domicile and 183 days in mainland China, green card and substantial presence in the US, 180/300 days in Hong Kong, residential ties in Canada, 183 days in Singapore. Results are a first-pass comparison only.
Tax residency decides whether a jurisdiction taxes you on worldwide income or mainly on locally sourced income, and which side you sit on under a tax treaty. The rules vary widely, so China's 183 days can't be applied everywhere. This check covers the common tests in mainland China, the US, Hong Kong, Canada and Singapore, and gives a first-pass comparison only.
Mainland China: an individual with a domicile in China is normally a resident individual. Without a domicile, spending a cumulative 183 days in China in a tax year generally also makes you a resident. If you hit 183 days for several years in a row, the "six-year rule" comes in: fewer than six consecutive years of 183 days, with a single trip abroad of more than 30 days, can affect whether foreign-source income is taxed in China. That threshold needs its own calculation. United States: citizens and green card holders are normally tax residents, taxed on worldwide income. Everyone else faces the substantial presence test (SPT): at least 31 days in the US in the current year, and (current year ×1 + prior year ×1/3 + the year before ×1/6) of 183 or more, usually makes you a resident.
Hong Kong has no concept of an individual "resident" taxed on worldwide income; Profits Tax and Salaries Tax follow the source of income. When claiming Hong Kong residence under a tax treaty, the usual day-count tests are more than 180 days in a year of assessment, or more than 300 days across two consecutive years of assessment (one being the relevant year). Canada looks at significant residential ties (a home, a spouse or partner, dependants) and also deems you resident if you spend 183 days or more in a year. Singapore is fairly clear: living or working there 183 days or more in a tax year usually makes you a tax resident. If two countries both treat you as resident, the treaty tie-breaker rules decide, comparing permanent home, centre of vital interests, habitual abode and nationality in turn. Filing each side as if nothing overlaps is not an option.
Without a domicile, 183 days in China in a tax year usually makes you a resident individual, which brings worldwide income into scope. Whether every type of foreign income must be included that year, and the exceptions under the six-year rule, depend on your consecutive years of residence and your departure records. "183 days" alone doesn't settle it.
Days in the current year count at 1×, prior-year days at 1/3 and days from the year before that at 1/6. If the total is 183 or more and you were present at least 31 days in the current year, you are usually an SPT resident. The tool's options follow this structure.
No, they are not a Profits Tax rate threshold. Hong Kong Profits Tax depends on whether profits arise in Hong Kong; 180/300 days are the usual presence tests for claiming Hong Kong residence under a tax treaty. Salaries Tax, Profits Tax and treaty residence should be looked at separately.
Yes. With no significant residential ties, 183 days or more in a year can still make you a deemed resident. Conversely, with a home or family ties in Canada you can be a factual resident even under 183 days.
This is a rules comparison, not a determination by a tax authority. It shows which side your answers lean toward and what day-count and ties evidence you should gather. Formal status, treaty relief and how to complete returns depend on the full facts and local rules.