Yojana (yojana) - Unit Information & Conversion

Definition

The Yojana (Sanskrit: योजन) is an ancient Indian unit of distance, primarily found in historical texts from South Asia. Its exact length is highly debated and likely varied significantly across different time periods, geographical regions, and textual sources.

There is no single, universally accepted conversion to modern units. Common scholarly estimates place its value anywhere between:

• 8 to 15 kilometers (km)
• Approximately 5 to 9 miles (mi)

Some ancient texts define the Yojana in terms of smaller units, such as:

• 4 krosas (or gorutas)
• 8,000 dhanus ('bows')
• 32,000 hastas ('cubits')

However, the lengths of these base units are also subject to historical variation and interpretation, contributing to the uncertainty surrounding the Yojana.

History

• Ancient Origins: The term "Yojana" appears in some of the oldest Indian literature, including the Vedas, the Puranas, and the great epics like the Ramayana and Mahabharata. It was a standard measure for long distances.
• Buddhist Texts: Buddhist scriptures, such as the Pali Canon, frequently use the Yojana to describe geographical distances, the dimensions of mythical realms, or the extent of a Buddha's journey. Different Buddhist traditions sometimes offer varying interpretations of its length.
• Arthashastra: Kautilya's Arthashastra (an ancient treatise on statecraft, c. 3rd century BCE) provides definitions relating the Yojana to smaller units, suggesting a more standardized system for administrative purposes at that time, though its precise value remains debated.
• Lack of Standardization: Unlike modern systems, ancient Indian measurements were not centrally standardized across the vast subcontinent and over long periods. Local customs, royal decrees, and the specific context (e.g., measuring road distance vs. cosmological scale) could all influence the intended length.
• Interpretations: Modern scholars have attempted to calculate the Yojana based on various methods:
  • Analyzing travel times mentioned in texts.
  • Comparing described geographical distances with known locations.
  • Relating it to astronomical measurements found in cosmological texts.
  • Working backward from definitions based on smaller, slightly better-understood units like the hasta (cubit) or angula (finger width). These methods often yield conflicting results.
• Obsolescence: With the advent of standardized systems like the Imperial system during British rule and later the widespread adoption of the metric system, the Yojana fell out of practical use for measurement.

Common Uses

The Yojana is primarily encountered today in:

• Historical Studies: Understanding ancient Indian geography, trade routes, military campaigns, and administrative divisions described in texts.
• Religious and Literary Studies: Interpreting distances mentioned in Hindu, Buddhist, and Jain scriptures, epics, and classical literature. This includes cosmological descriptions, mythological journeys, and the size of ancient kingdoms or structures.
• Cultural Context: It remains a part of the cultural lexicon in discussions related to ancient Indian heritage and texts.

It is not used for any practical, scientific, or commercial measurements in the modern era.

Unit FAQs

What is the accepted value of a Yojana in modern units?

There is no single universally accepted value. Scholarly estimates vary widely, most commonly falling between 8 kilometers (approx. 5 miles) and 15 kilometers (approx. 9 miles). Some interpretations suggest values as low as 5 km or as high as 20 km. The specific text, time period, and region must be considered.

Why is the length of the Yojana so uncertain?

Several factors contribute to the uncertainty:

1. Lack of Central Standardization: Ancient India had diverse local measurement practices.
2. Evolution Over Time: The definition likely changed over centuries.
3. Variable Base Units: The smaller units (like krosa or hasta) used to define it were also not universally fixed.
4. Contextual Differences: The term might have been used differently for road distances, land surveys, or cosmological scales.
5. Figurative Use: In some literary or religious contexts, the term might have been used symbolically or hyperbolically rather than as a precise measurement.

How does the Yojana relate to other ancient Indian units?

The Yojana was typically the largest unit in a hierarchical system. A common (though not universal) relationship described in texts like the Arthashastra is:

• 1 Yojana = 4 Krosas (or Gorutas)
• 1 Krosa = 1,000 (or sometimes 2,000) Dhanus (bows)
• 1 Dhanus = 4 Hastas (cubits)
• 1 Hasta = 24 Angulas (finger widths)

The uncertainty in the base units (hasta, angula) contributes to the uncertainty in the Yojana.

Is the Yojana still used today?

No, the Yojana is an obsolete unit of measurement. It has not been used for practical purposes for centuries and has been entirely replaced by the metric system (kilometers, meters) in India and other relevant regions. Its relevance is purely historical, literary, and cultural.

Is the Yojana an SI unit?

No, the Yojana is not an SI unit. It is an ancient, traditional unit of distance from the Indian subcontinent. The SI base unit for length is the meter (m).