# Ancient Thai units of measure

Many of the following historical Thai units of measurement are no longer used today. However, they often appear in ancient texts and chronicles . Occasionally one also finds units according to the Anglo-American measurement system .

The units of measurement used in Thailand today are based on the metric system according to the International System of Units , which is valid worldwide. The metric system was introduced by the law of December 17, 1923. Traditional measurements were adjusted and given "smooth" metric values.

In some professional groups, trades and branches, the historical units of measurement are used more often than the metric measures. In the agricultural and real estate sectors, for example, only the unit Rai is used as the area measure . Craftsmen, especially in the construction industry, use the length measure Nio (translated: finger, corresponds to an inch = 2.54 cm) more often than centimeters. All tape measures have a double scale: in Nio and in cm.

In the timber trade, squared lumber, rods or boards are only measured and billed in Sok (= cubits ), while wooden panels are only measured in cm. Carpenter's shops or sawmills always calculate their wages for long and straight parts according to the Sok. Lengths in Sok are usually given in even numbers, at most half a Sok is taken into account and rounded.

In Thai real estate deeds and in legal documents, even in recently written ones, property sizes are always given analogously to the following example: 28 Rai 2 Ngan 6 Tarang Wa.

Hun is a historical unit of measurement for diameter. It is used by craftsmen and corresponds to 3 mm.

Baht is used exclusively to indicate the weight of gold and silver and pieces made from them.

## Length measurements

Surname Thai metric
1 kabiat กระเบียด 05 mm
1 nio (" finger " or inch ) = 4 kabiat นิ้ว 02 cm
1 Khuep ( span ) = 12 nio คืบ 25 cm
1 sok ( cubit ) = 2 khuep ศอก 50 cm
1 Wa ( fathom ) = 4 Sok วา 02 m
1 Sen ("rope") = 20 Wa เส้น 40 m
1 Yot (from Sanskrit Yojana ) = 400 Sen โยชน์ 16 km

## Area dimensions

Surname Thai metric
1 Tarang Wa (1 Wa 2 ) ตาราง วา 0004 m 2
1 Ngan = 100 Wa 2 งาน 0400 m 2
1 rai = 4 ngan ไร่ 1600 m 2
6.25 rai 10000 m 2 = 1 hectare

## Weight measurements

Surname Thai metric
2 Fueang = 1 Salueng เฟื้อง 03.75 g
4 salueng = 1 baht สลึง 15 g
1 baht บาท 15 g
1 tamlueng = 4 baht ตำลึง 60 g
1 Chang ( Kati ) = 20 Tamlueng ชั่ง 01.2 kg
1 hap (picul) = 50 chang หา บ 60 kg

## Rice weight measurements

Surname Thai metric
1 coyan = 16 piculi of unpeeled rice 0968 kg
1 coyan = 22 piculi of cargo rice 1330 kg
1 kwian = 23 piculi of white rice เกวียน (ข้าวเปลือก) 1391 kg
1 kwian of a rice miller: 82 baskets of 40 pounds = 24 piculi 1488 kg

## Volume measurements

Surname Thai metric
1 thanane ทะนาน 0001 liter
1 Sat = 20 Thanan 0020 liters
1 ban = 50 sat 1000 liters
1 Kwian = 2 Ban เกวียน 2000 liters

## swell

1. Minutes of the 7th General Conference on Weights and Measures , 1927, p. 67, accessed November 9, 2019