Add each stay with its arrival and departure date. The counter adds up the days in Thailand for each calendar year and shows where you stand against the 180-day rule.
The rule
The Revenue Department treats you as a Thai tax resident for a calendar year if you are in Thailand for 180 days or more between 1 January and 31 December, in one stay or several added together. Each calendar year counts on its own: the department's own example is a stay of 250 days split 100 and 150 across two years, which makes the person resident in neither year.
How the counter counts: the Revenue Department gives no rule on whether arrival and departure days count. To be on the safe side, the counter counts both as full days in Thailand. Being a tax resident does not by itself mean you owe tax; what is taxable depends on your income and any tax treaty.
This is a counting aid, not tax advice. Read our guide to Thai tax residency and foreign income and ask a tax adviser about your own case.
Source
- Revenue Department – Legal Affairs Division Q&A on tax residence (2024) (checked 1 October 2026)