Thai tone rules explained

Thai has five spoken tones — mid, low, falling, high and rising — but the script does not show them directly. Instead, the tone of a syllable is determined by four things: the consonant class, whether the syllable is "live" or "dead", vowel length, and any tone mark.

The five Thai tones

The same syllable shape, spoken with each tone, can change meaning entirely. Tap a pill to hear the classic "ปา" set if your browser supports audio.

ปาป่าป้าป๊าป๋า

Consonant classes

Thai consonants belong to one of three classes. The class is the starting point for every tone calculation.

ClassConsonantsRule shortcut
midก จ ฎ ฏ ด ต บ ป อNo tone mark = mid tone; with a mark they follow the mark's rule.
highข ฃ ฉ ฐ ถ ผ ฝ ศ ษ ส หNo mark on a live syllable = rising; a dead syllable = low, regardless of vowel length.
lowค ฅ ฆ ง ช ซ ฌ ญ ฑ ฒ ณ ท ธ น พ ฟ ภ ม ย ร ล ว ฬ ฮNo mark on a live syllable = mid; no mark on a dead long = falling; no mark on a dead short = high.

The silent leading consonants and can raise a following low-class sonorant to high or mid class: หมา (high class, rising tone) vs มา (low class, mid tone).

Live and dead syllables

A syllable is live if it ends in a long vowel, a diphthong, or a sonorant final consonant (ม, น, ง, ย, ว, ร, ล). It is dead if it ends in a stop final (ก, ด, บ, etc.) or a short vowel with no final.

Live syllables

  • Long vowel, no final: กา, มี, ตู้
  • Any vowel + sonorant final: กาง, คน, ยม
  • Diphthongs such as เ–า, ไ–, ใ– are always live

Dead syllables

  • Short vowel, no final: กะ, ปิ๊ก, ตุ๊ก
  • Any vowel + stop final: ปัก, ผัด, รับ
  • Stop-final syllables may have either a short or long vowel

Vowel length matters

For dead syllables, the vowel length decides between two possible tones. A dead syllable with a short vowel gets a different tone than a dead syllable with a long vowel.

ClassDead + short vowelDead + long vowel
MidLowLow
HighLowFalling
LowHighFalling

Tone marks override the class

The four tone marks sit on the consonant and set the tone directly — with one exception: on a low-class consonant, (mai ek) gives a falling tone and (mai tho) gives a high tone.

ป่า

mai ek () — Low

ป้า

mai tho () — Falling

ป๊า

mai tri () — High

ป๋า

mai chattawa () — Rising

Full Thai tone rules table

Tone marks are not shown here; when present, use the tone mark table above.

Consonant classLive syllableDead + short vowelDead + long vowel
midMidLowLow
highRisingLowLow
lowMidHighFalling

Colour-coded examples

Each word below is automatically coloured by the same engine used in the reader.

Mid tone examples

กาจานตีคนปลา

Low tone examples

ป่าต่ำผัดขัดฝาก

Falling tone examples

ป้าก้ามากค่าท่า

High tone examples

ป๊าม้าน้าค๊าท้า

Rising tone examples

ขาหมาผลถุงสา

Put the rules into practice

Paste any Thai text into the reader and see every syllable coloured by its tone instantly.