RTGS Romanization Guide

A detailed overview of the Royal Thai General System of Transcription

Thai Script Components

Consonant Classes

Thai consonants are divided into three classes based on their origin and pronunciation characteristics:

  • Mid Class: 16 consonants that produce mid-class tones when unaspirated
  • High Class: 14 consonants that typically produce high-class tones
  • Low Class: 17 consonants that typically produce low-class tones

The class affects the tone of the syllable when combined with vowel length and tone marks.

Vowel Characteristics

Thai vowels are categorized by length and position:

  • Short Vowels: Pronounced quickly with a brief sound
  • Long Vowels: Sustained with a longer sound
  • Compound Vowels: Complex combinations of basic vowels

Vowel length is crucial for determining the tone of a syllable in Thai.

Tone System

Thai is a tonal language with five distinct tones:

  • Mid Tone: The base tone (no mark)
  • Low Tone: Lower in pitch than mid tone (่)
  • Falling Tone: Starts high and falls (้)
  • High Tone: Higher in pitch than mid tone (๊)
  • Rising Tone: Starts low and rises (๋)

Tone is determined by the interaction of consonant class, vowel length, and tone marks.

Consonant Transliteration

Thai Character Initial Position Final Position Class
ก k k Mid
ข ฃ ค ฅ ฆ kh k High/Low
ง ng ng Low
จ ch t Mid
ฉ ช ฌ ch t High
ซ ศ ษ ส s t High
ญ y n Low
ฎ ด d t Mid
ฏ ต t t Mid
ฐ ฑ ฒ ถ ท ธ th t High/Low
ณ น n n Low
บ b p Mid
ป p p Mid
ผ พ ภ ph p High/Low
ฝ ฟ f p High
ม m m Low
ย y - Low
ร r n Low
ล ฬ l n Low
ว w - Low
ห h - High
อ - - Mid

Vowel Transliteration

Thai Character Romanization Length
ะ ั a short
า a long
ิ i short
ี i long
ึ ue short
ื ue long
ุ u short
ู u long
เ e long
แ ae long
โ o long
ใ ไ ai long
ำ am long
ฤ ฦ rue/lue short
ฤๅ ฦๅ rue/lue long
เีย ia long
เือ uea long
ัว ua long
เา ao long

Using Our Romanization Tool

Word Segmentation

Our improved algorithm uses the Wordcut library to better handle word boundaries in Thai text for more accurate romanization.

Tone Options

Toggle between showing tone marks as diacritical accents (à, á, â, ǎ) or using the basic RTGS without tone indicators.

History Feature

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