Span to Wa Conversion Calculator: Free Online Tool

Convert spans to wa with our free online length converter.

Span to Wa Calculator

Span
Wa

How to Use the Calculator:

  1. Enter the value you want to convert in the 'From' field (Span).
  2. The converted value in Wa will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Length category.
  4. Click the swap button (⇌) to reverse the conversion direction.

How to Convert Span to Wa

Converting Span to Wa involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Span = 0.1143 wa

Example Calculation:

Convert 10 spans: 10 × 0.1143 = 1.143 wa

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Span and a Wa?

The Span is an ancient unit of length based on the distance across an outstretched human hand, measured from the tip of the thumb to the tip of the little finger (or sometimes the index finger). As an anthropomorphic unit, its length was inherently variable, depending on the size of an individual's hand.

Historically, it was often defined in relation to other body-based units:

  • Typically considered half a cubit.
  • Often equated to 3 palms (where a palm is the width of the hand across the base of the fingers).
  • Sometimes defined as 12 digits (fingerbreadths).

A common, though unofficial, modern estimate for a span is around 9 inches or approximately 22.86 centimeters (cm).

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).

Note: The Span is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Wa belongs to the imperial/US customary system.

History of the Span and Wa

The span is one of the oldest informal units of measurement, used by numerous ancient civilizations, including the Egyptians, Israelites, Greeks, and Romans, due to the convenience of using the human hand.

  • Ancient Egypt & Mesopotamia: The span was used alongside the cubit and digit. The relationship (often 1 span = 1/2 cubit) was fundamental in their systems.
  • Biblical References: The span is mentioned in the Bible (e.g., Exodus 28:16 describing the High Priest's breastplate, Goliath's height in some interpretations).
  • Ancient Greece & Rome: Used as a practical subdivision of the cubit.
  • Medieval Europe: Continued in informal use and sometimes appeared in texts defining lengths. In England, it was often standardized (unofficially) as 9 inches.

Like other anthropomorphic units, the span fell out of official use with the development and adoption of more standardized systems like the Imperial (inches, feet) and Metric (meters) systems, which provided necessary precision for trade, science, and industry.

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 for spans and wa

Explore the typical applications for both Span (imperial/US) and Wa (imperial/US) to understand their common contexts.

Common Uses for spans

The span is now obsolete for precise or official measurements but is still encountered or used in specific contexts:

  • Informal Estimation: Used for quick, rough measurements of moderate lengths where precision is not critical (e.g., gardening, crafts, estimating object sizes).
  • Historical Texts: Found in ancient and medieval documents, requiring understanding for interpretation.
  • Anthropology & Archaeology: Relevant when studying historical measurement systems or interpreting dimensions from ancient sites.
  • Figurative Language: Can be used metaphorically to denote a small distance or extent ("life span").
  • Understanding Historical Units: Key to grasping the relationship between units like the digit, palm, and cubit in ancient systems.

Common Uses for wa

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.

Frequently Asked Questions

Questions About Span (span)

How long is a span?

There is no single, universally fixed length for a span because it's based on human hand size. However:

  • A common historical and modern estimate is 9 inches (in).
  • This is approximately 22.86 centimeters (cm) or 0.2286 meters (m).
  • Historically, it was often defined as half a cubit, which varied (e.g., a common cubit of ~18 inches would yield a 9-inch span).

What is the relationship between a span and a cubit?

In many historical systems, a span was considered half (1/2) of a cubit. Since cubits themselves varied (e.g., common cubit vs. royal cubit), the exact length of the span derived this way also varied.

What is the relationship between a span and a palm or digit?

Common relationships, though varying by system, were:

  • 1 span ≈ 3 palms (where a palm is the width of the hand).
  • 1 span ≈ 12 digits (where a digit is the width of a finger).

Is the span an SI unit?

No, the span is not an SI unit. It is an ancient, non-standardized, anthropomorphic unit. The SI base unit for length is the meter (m).

Is the span still used today?

The span is not used for any official, scientific, or commercial measurements. Its use is limited to informal estimations, historical context, and figurative language. People might still use their own hand span for a quick size check.

Where does the name 'span' come from?

The word "span" comes from Old English spann, related to the verb spannan, meaning "to stretch, extend, or connect". This directly reflects the action of stretching the hand to measure the unit.

About Wa (wa)

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.

Conversion Table: Span to Wa

Span (span)Wa (wa)
10.114
50.572
101.143
252.858
505.715
10011.43
50057.15
1,000114.3

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