How it works
Type a year in either the B.E. or A.D. box and the other fills in automatically. To see the weekday or how a date is written in Thai, pick a full date below.
Formula
B.E. = A.D. + 543
A.D. = B.E. − 543
FAQ
What is the difference between B.E. and A.D.?
The Thai Buddhist Era is 543 years ahead: B.E. = A.D. + 543 and A.D. = B.E. − 543. For example, 2026 A.D. is 2569 B.E.
Why do some old Thai documents seem one year off?
Before 2484 B.E. (1941), the Thai new year started on 1 April, so dates from 1 January to 31 March in earlier years have a B.E. year one lower than +543 suggests. This tool uses the modern system (new year on 1 January).
Where will I see B.E. years in Thailand?
Almost everywhere official: ID cards, contracts, receipts, tax forms and expiry dates on products use B.E. years. Subtract 543 to get the year you are used to.
How should software store Thai dates?
Store dates in A.D. (ISO format, e.g. 2026-10-08) and convert to B.E. only when displaying, to avoid dates shifting by 543 years.