Free Thai Buddhist Era (BE) Year & Date Converter

Worked example

A Thai document is dated 24/02/70 and you need the English date. In "Quick convert" the two-digit year is read as พ.ศ. 2570, which is 2027 CE, so the answer is 24 February 2027, with the weekday and the Thai written form. The same box turns 1 กรกฎาคม 2569 into 1 July 2026. A line under the result says which era the tool assumed, so you can check it before you copy.

Which settings to use, and the limits

• Use "Quick convert" first. Type a year (2569) or a full date (24/02/2570, 1 July 2569, 2026-09-30) in the box. Thai digits and Thai or English month names work. Dates are read day first, and the tool shows what it assumed.
• Mind the auto-detected era. With the Thailand preset, a year of 2400 or higher is read as BE and a lower one as CE. A BE year below 2400 (for example 2300) therefore needs the "Read as BE instead" button, or write พ.ศ. or BE next to it.
• Two-digit years mean BE. 24/02/70 is read as 2570 BE (2027 CE), the way Thai forms are written. For 1970, type four digits (24/02/1970). Adding CE to a two-digit year reads it as 20xx.
• Pick the right "Era offset" under "More options". The presets are Thailand / Laos / Cambodia (+543), Myanmar / Sri Lanka (+544) and Chula Sakarat (+1182). Keep +543 for Thai paperwork. "CE → BE" and "BE → CE" set the direction, and flipping it converts the year already in the field.
• Copy the format your form wants. A date result lists numeric formats (DD/MM/YYYY, YYYY-MM-DD and others) and Thai document formats such as วัน…ที่ 24 กุมภาพันธ์ พ.ศ. 2570, with an option for Thai numerals. "Convert a list (batch)" handles up to 100 lines, which you can copy as TSV or CSV for a spreadsheet.
• Check pre-1941 dates. Before 1941 the Thai civil year began on 1 April. For a January to March date earlier than that, the official Thai year on an old document is one lower than +543 gives. The tool uses the modern January start and shows a note in that case.

Common problems and how to fix them

It says "Not recognised. Try 2569, 24/02/2570 or 1 July 2569."

Give a lone year or a full day, month and year. A month and year alone (July 2569) cannot be converted exactly, so add the day. Remove extra words other than an era tag (พ.ศ., ค.ศ., BE, CE) and weekday names.

It says "That day does not exist in that month."

Check the day against the month and the leap year. 29/02/2569 is invalid because 2569 BE is 2026 CE, which is not a leap year; 29/02/2567 (2024 CE) is valid. Leap years follow the Gregorian rule.

The result is 543 years off from what I expected.

The year was probably read in the other era. Look at the "Interpreted as" line and press "Read as … instead". You can also put พ.ศ. or CE after the year.

The day and month came out swapped.

Dates are read day first. If the middle number is above 12, the tool reads it as month/day and says so. For a date like 03/04/2569, which could be read either way, write the month as a word or use YYYY-MM-DD.

Year only mode says "Enter a whole number year."

That mode takes digits with an optional minus sign. Remove spaces, decimals and era text, or use "Quick convert", which accepts พ.ศ. and BE.

How it compares

Converting between the Thai Buddhist calendar and the Gregorian one is only a change of year number, because both use the same months, days and weekdays. That makes it much simpler than converting to a lunar calendar. Lunar festival dates such as Visakha Bucha are outside what this tool does.