Thailand’s official year numbering follows the Buddhist Era (B.E.), which is 543 years ahead of the Gregorian Anno Domini (A.D.) system. This difference means that when Western calendars show A.D. 2025, Thai calendars display B.E. 2568. Understanding this conversion is useful not only for travellers and historians but also for anyone interacting with Thai documents and websites.
Conversion Rule
The conversion is straightforward because the difference between the two systems is constant:
To convert A.D. → B.E.: add 543. For example, 2025 + 543 = 2568.
To convert B.E. → A.D.: subtract 543. For example, 2568 − 543 = 2025.
Because the Thai calendar uses the same months and days as the Gregorian calendar for civil purposes, the day and month stay unchanged when converting between years. Only the numerical year differs.
Historical Context
The Buddhist Era is counted from the traditional year of the Buddha’s passing, which Thai scholars place at 543 B.C.E. In 1888 Thailand adopted the Western-style solar calendar but kept the B.E. year numbering system. This hybrid approach allowed Thailand to integrate international trade and diplomatic relations while maintaining cultural identity. As noted in Thai legal documents and websites, you will often see both B.E. and A.D. years displayed together, particularly on official certificates and in news reports.
Tips for Using Thai Year Converters
Many online tools and mobile apps now include Thai year converters. When using them, remember that:
Years greater than 2500 are usually B.E.; years below 2500 are likely A.D.
For dates early in the 20th century (e.g., 1940 or B.E. 2483), the official New Year change from April 1 to January 1 (in 1941) may affect historical date references.
Armed with this simple conversion rule, you can confidently read Thai dates and convert historical and future events between Buddhist Era and Gregorian years.