Numbers in Thai: zero to a million, Thai digits ๐–๙ and counting rules

How the numbers in Thai are put together

Once the first ten are known, most numbers in Thai assemble themselves. A multiple of ten is the digit followed by สิบ: สามสิบ, three ten, is thirty, and แปดสิบ is eighty. The units follow the tens, so thirty-four is สามสิบสี่, sam sip si. The same logic continues upward: the Thai numerals article gives 232 as สองร้อยสามสิบสอง, song roi sam sip song, two hundred three ten two.

Two words break the pattern. The first is เอ็ด (et). On its own, one is หนึ่ง, but when one is the final digit after a ten, Thai says et: eleven is สิบเอ็ด, twenty-one ยี่สิบเอ็ด, and the Thai numerals article advises ร้อยเอ็ด, roi et, for 101, because a plain roi nueng can be heard as one hundred. The article also notes that the Royal Thai Navy used nueng in every position, as in สิบหนึ่ง, to rule out mishearing.

The second is ยี่ (yi). The two of twenty is not สอง but ยี่, so twenty is ยี่สิบ and the twenties run ยี่สิบเอ็ด, ยี่สิบสอง and so on, while two hundred and two thousand go back to song: สองร้อย, สองพัน. In fast speech ยี่สิบ shrinks to something like yip, a shortening the Thai numerals article records.

One more detail catches learners: Thai never says หนึ่ง before สิบ. Ten is simply สิบ, where English has no choice either, but Thai keeps the rule inside larger numbers too, so 110 is ร้อยสิบ, one hundred ten, without a one in front of the ten.

Ten thousand, a hundred thousand and a million

English counts large numbers in thousands. Thai has a separate word for every power of ten up to a million: สิบ for ten, ร้อย for a hundred, พัน for a thousand, หมื่น (muen) for ten thousand, แสน (saen) for a hundred thousand and ล้าน (lan) for a million. A price of 45,000 baht is therefore สี่หมื่นห้าพัน, four ten-thousands five thousands, never forty-five thousand.

Above a million the series starts again, with ล้าน acting as a multiplier: the Thai numerals article gives ten million as สิบล้าน, sip lan, and a billion is a thousand millions, พันล้าน. Reading a long figure aloud is easiest by splitting it at the million and naming each place from the left.

Decimals and negatives use plain words. The decimal point is read จุด, chut, dot, and a minus sign is ลบ, lop, placed before the number, so the article's example for minus eleven is lop sip et. For fractions Thai uses ใน, in or of, between the two parts.

Thai digits ๐ to ๙ and where they still appear

Thai has its own set of digits, ๐ ๑ ๒ ๓ ๔ ๕ ๖ ๗ ๘ ๙, which follow the same decimal place-value system as the familiar 0 to 9, so ๒๕๖๙ is simply 2569 written in Thai shapes. The Thai numerals article describes them as the traditional digits of the country and notes that the Western digits are now the more common of the two.

Both sets live side by side. A Buddhist Era year such as ๒๕๖๙ reads as 2569 once the ten shapes are known, and since every Thai digit has an exact counterpart, a reader never has to convert, only to recognise. The numbers 1 to 10 in many languages table gives the Thai number words next to those of hundreds of other languages.

Counting with classifiers and saying first, second, third

Thai does not put a number straight in front of a noun. The Thai numerals article sums up the order: the noun comes first, then the number, then a classifier, a measure word chosen by the kind of thing counted. Two books, two people and two bottles therefore each take a different classifier after สอง, much as English says two loaves of bread or two head of cattle, only for every noun.

Ordinal numbers are the easiest part of the system. Thai puts ที่ (thi) before the cardinal number: ที่หนึ่ง, thi nueng, is first, ที่สอง, thi song, second, and ที่สาม third. Dates use the same word, so the 28th of a month is วันที่ 28, the day number 28, as the months in Thai page shows.

Tone marks in the Thai numbers

The first ten numbers in Thai are a good introduction to the four tone marks. สี่, four, carries mai ek, ่, and is said on a low tone; ห้า, five, and เก้า, nine, carry mai tho, ้, and fall. หนึ่ง has mai ek as well. The marks mai tri, ๊, and mai chattawa, ๋, do not occur in the numbers at all, and in the tone chart of the Wikipedia article on the Thai script they appear only with middle-class consonants.

What a mark does depends on the class of the consonant it sits on, high, middle or low, so the same mark can give different tones on different letters. Learners should take the IPA column above as the record of how each number sounds and the Thai spelling as the key to why.