Thai has one of the larger writing systems in everyday use: 44 consonant letters in three tone classes, dozens of vowel forms that wrap around consonants, and four tone marks on top of that. This reference gathers every character into searchable tables so you can look up any letter, its acrophonic name, its sound value, and its tone class.
The three consonant classes and why they matter
Every Thai consonant belongs to one of three classes — high, mid, or low — and this class is the single most important factor in determining which tone a syllable carries. The same vowel and even the same tone mark produce different tones depending on the class of the initial consonant.
Thai has five tones: mid, low, falling, high, and rising. The tone of a syllable is determined by the combination of:
initial consonant class × syllable type (live or dead) × tone mark (if any)For example, a mid-class consonant in a live syllable with no tone mark produces a mid tone. The same live syllable with a low-class initial consonant produces a rising tone. This is why memorising consonant classes is the most leverage-per-effort investment for anyone learning to read Thai.
Consonant class distribution
The 44 consonants are distributed as follows:
- High class — 11 consonants including ข ฉ ถ ผ ฝ ส ห
- Mid class — 9 consonants including ก จ ด ต บ ป อ
- Low class — 24 consonants, the largest group, including ง ณ น ม ร ล ว and many others
Because 44 letters represent only 21 distinct consonant sounds, many letters share the same sound value. They are distinguished by their class and by their acrophonic names — for example ก (ko kai, “chicken k”), ข (kho khai, “egg k”), and ค (kho khwai, “buffalo k”) all sound like /k/ initially but belong to different classes, producing different tones.
Vowels in Thai
Thai vowels are not stand-alone letters placed in a sequence like the alphabet. They are diacritic-like forms placed in four positions relative to the consonant they modify:
- Before the consonant: เ แ โ ใ ไ (leading vowels)
- Above the consonant: ◌ิ ◌ี ◌ึ ◌ื and others
- Below the consonant: ◌ุ ◌ู
- After the consonant: า ◌ า ว
- Surrounding the consonant: เ◌า เ◌ีย เ◌ือ and compound forms
In the vowel table, a dash placeholder shows where the consonant sits relative to the vowel sign.
Tone marks
The four Thai tone marks (ไม้เอก ่, ไม้โท ้, ไม้ตรี ๊, ไม้จัตวา ๋) are placed above the initial consonant or the consonant that closes the syllable. Because they interact with consonant class, the same mark on a high-class consonant produces a different tone than on a low-class one — making the tone mark tables essential once you move beyond basic reading. The two obsolete consonants ฃ and ฅ are included in the table for historical completeness but are no longer used in modern Thai writing.