Wa (wa) - Unit Information & Conversion

Symbol:wa

Plural:wa

Category:Length

What is a Wa?

Definition

The Wa (วา) is a traditional Thai unit of length. It is legally defined in relation to the metric system as exactly 2 meters.

The Wa serves as a fundamental unit within the traditional Thai system of measurement, particularly for land area. It is roughly equivalent to the distance between a person's outstretched fingertips when their arms are extended horizontally to the sides (similar to a fathom).

History

The Wa has been used in Thailand (formerly Siam) for centuries, likely originating from anthropomorphic measurements like the arm span. It was a practical unit for everyday measurements, construction, and land surveying.

Traditional System: The Wa was part of a system that included smaller units like the khuep (span, ~25 cm), sok (cubit, ~50 cm, 1 Wa = 4 Sok), and larger units like the sen (rope, 1 Sen = 20 Wa).
Standardization: During the modernization reforms under King Chulalongkorn (Rama V) in the late 19th and early 20th centuries, Thailand began standardizing its weights and measures. The Weights and Measures Act of 1923 formally defined traditional units in terms of the metric system. The Wa was officially set at exactly 2 meters.
Metrication: While Thailand officially adopted the metric system as its primary standard, traditional units like the Wa remain legally defined and widely used, especially in specific contexts like land measurement.

Common Uses

The Wa's most significant modern use is in land measurement, but it historically had broader applications:

Land Area: This is the most common contemporary use. Land area in Thailand is almost exclusively measured in Tarang Wa (ตารางวา - Square Wa).
- 1 Tarang Wa = 4 square meters (2m x 2m)
- 1 Ngan (งาน) = 100 Tarang Wa (400 sq m)
- 1 Rai (ไร่) = 4 Ngan = 400 Tarang Wa (1600 sq m) Property deeds, real estate listings, and land surveys invariably use Rai, Ngan, and Tarang Wa.
Length Measurement: While meters are now standard for most length measurements (textiles, construction materials), the Wa might still be used informally or in traditional contexts. Historically, it was used for measuring distances, building dimensions, rope lengths, etc.
Construction & Architecture: Traditionally used for laying out building plots and determining dimensions in Thai architecture.
Cultural Context: Understanding the Wa and its related area units is essential for navigating real estate, agriculture, and historical contexts in Thailand.

Unit FAQs

How long is a Wa?

A Wa is defined as exactly:

2 meters (m)
200 centimeters (cm)
Approximately 6.5617 feet (ft)
Approximately 78.74 inches (in)

What are the related traditional Thai length units?

The Wa fits into a system, often based on factors of 2 and 10:

Smaller Units:
- 1 Wa = 4 Sok (ศอก - cubit, ~50 cm)
- 1 Sok = 2 Khuep (คืบ - span, ~25 cm)
- 1 Khuep = 12 Nio (นิ้ว - finger breadth, ~2.08 cm, not the English inch)
Larger Unit:
- 1 Sen (เส้น - rope/chain) = 20 Wa (40 meters)
- 1 Yot (โยชน์ - league) = 400 Sen (16 kilometers)

How is the Wa used for area measurement?

The primary unit for land area is the Tarang Wa (Square Wa):

1 Tarang Wa = 1 Wa × 1 Wa = 2 m × 2 m = 4 square meters Larger area units are based on the Tarang Wa:
1 Ngan = 100 Tarang Wa (400 m²)
1 Rai = 4 Ngan = 400 Tarang Wa (1600 m²)
(For reference, 1 Acre ≈ 2.53 Rai, 1 Hectare = 6.25 Rai)

Is the Wa an SI unit?

No, the Wa is not an SI unit. It is a traditional Thai unit, although its legal definition is based on the SI unit, the meter (m).

Is the Wa still used today?

Yes, absolutely. While the metric system is the official standard for science, commerce, and industry, the Wa (especially as Tarang Wa for area) remains the standard unit for land measurement in Thailand. It is legally recognized and used in all official land documents and real estate transactions. Its use for linear measurement is less common but may still occur informally or in traditional settings.

Wa Conversion Formulas

To Meter:

1 wa = 2 m

Example: 5 wa = 10 meters

To Kilometer:

1 wa = 0.002 km

Example: 5 wa = 0.01 kilometers

To Hectometer:

1 wa = 0.02 hm

Example: 5 wa = 0.1 hectometers

To Decimeter:

1 wa = 20 dm

Example: 5 wa = 100 decimeters

To Centimeter:

1 wa = 200 cm

Example: 5 wa = 1000 centimeters

To Millimeter:

1 wa = 2000 mm

Example: 5 wa = 10000 millimeters

To Inch:

1 wa = 78.740157 in

Example: 5 wa = 393.700787 inches

To Foot:

1 wa = 6.56168 ft

Example: 5 wa = 32.808399 feet

To Yard:

1 wa = 2.187227 yd

Example: 5 wa = 10.936133 yards

To Mile:

1 wa = 0.001243 mi

Example: 5 wa = 0.006214 miles

To Nautical Mile:

1 wa = 0.00108 NM

Example: 5 wa = 0.0054 nautical miles

To Micrometer:

1 wa = 2000000 μm

Example: 5 wa = 10000000 micrometers

To Nanometer:

1 wa = 2000000000 nm

Example: 5 wa = 10000000000 nanometers

To Light Year:

1 wa = 2.1139e-16 ly

Example: 5 wa = 1.0570e-15 light years

To Astronomical Unit:

1 wa = 1.3369e-11 AU

Example: 5 wa = 6.6845e-11 astronomical units

To Parsec:

1 wa = 6.4815e-17 pc

Example: 5 wa = 3.2408e-16 parsecs

To Angstrom:

1 wa = 20000000000 Å

Example: 5 wa = 100000000000 angstroms

To Point (Typography):

1 wa = 5669.287767 pt

Example: 5 wa = 28346.438837 points

To Mil/Thou:

1 wa = 78740.15748 mil

Example: 5 wa = 393700.787402 mils

To Fathom:

1 wa = 1.093613 fath

Example: 5 wa = 5.468066 fathoms

To Furlong:

1 wa = 0.009942 fur

Example: 5 wa = 0.04971 furlongs

To Link (Gunter's):

1 wa = 9.941939 li

Example: 5 wa = 49.709695 links

To Pace:

1 wa = 2.624672 pace

Example: 5 wa = 13.12336 paces

To Span:

1 wa = 8.748906 span

Example: 5 wa = 43.744532 spans

To Digit:

1 wa = 104.986877 digit

Example: 5 wa = 524.934383 digits

To Cable Length:

1 wa = 0.010799 cb

Example: 5 wa = 0.053996 cable lengths

To Ell:

1 wa = 1.749781 ell

Example: 5 wa = 8.748906 ells

To Finger:

1 wa = 17.497813 finger

Example: 5 wa = 87.489064 fingers

To Roman Mile:

1 wa = 0.001351 m.p.

Example: 5 wa = 0.006757 Roman miles

To Stadion:

1 wa = 0.010811 stadion

Example: 5 wa = 0.054054 stadia

To Chi (Chinese):

1 wa = 6.0006 chi

Example: 5 wa = 30.003 chi

To Shaku (Japanese):

1 wa = 6.60066 shaku

Example: 5 wa = 33.0033 shaku

To Li (Chinese):

1 wa = 0.004 li

Example: 5 wa = 0.02 li

To Toise:

1 wa = 1.026167 toise

Example: 5 wa = 5.130836 toise

To Bolt:

1 wa = 0.065617 bolt

Example: 5 wa = 0.328084 bolts

To Rope:

1 wa = 0.328084 rope

Example: 5 wa = 1.64042 ropes

To Smoot:

1 wa = 1.175226 smoot

Example: 5 wa = 5.876131 smoots

To Sajene:

1 wa = 0.937383 sajene

Example: 5 wa = 4.686914 sajenes

To Ken:

1 wa = 1.10011 ken

Example: 5 wa = 5.50055 ken

To Vara:

1 wa = 2.386065 vara

Example: 5 wa = 11.930327 varas

To Aln:

1 wa = 3.367003 aln

Example: 5 wa = 16.835017 alnar

To Cubit (Royal/Egyptian):

1 wa = 3.824092 cubit

Example: 5 wa = 19.120459 cubits

To Versta:

1 wa = 0.001875 versta

Example: 5 wa = 0.009374 versts

To Arpent:

1 wa = 0.034205 arpent

Example: 5 wa = 0.171025 arpents

To Ri (Japanese):

1 wa = 0.000509 ri

Example: 5 wa = 0.002546 ri

To Klafter:

1 wa = 1.054574 klafter

Example: 5 wa = 5.272871 klafter

To Yojana:

1 wa = 0.000148 yojana

Example: 5 wa = 0.000741 yojanas

To Skein:

1 wa = 0.018227 skein

Example: 5 wa = 0.091134 skeins

Convert Wa

Need to convert Wa to other length units? Use our conversion tool.

Go to Length Converter Convert from Wa