A Yojana (Sanskrit : योजन ) is a Vedic measure of distance that was used in ancient India. It is equivalent to about 1.6 km (1 mi) as per modern measures of distance, although the exact value is disputed among scholars (between 2 and 5 km (1 and 3 mi)).
In modern Hindi the word yojanaa (Hindi : योजना) means "plan" or blueprint, and is etymologically connected with the Cartesian notion of distance in the word yojana. However, note that the words "yojana'" and "yojanaa" are different, and pronounced differently. The last sound of the second word is pronounced "aaa" as in arm [ārm].
Variations on length
The length of the yojana varies depending on the different standards adopted by different Indian astronomers. In the Surya Siddhanta of the 5th century, for example, a yojana was equivalent to 8.0 km (5 mi), and the same was true for Aryabhata's Aryabhatteeya (499). However, 14th century scholar Paramesvara defined the yojana to be about 1.5 times larger, equivalent to about 13 km (8 mi). A. C. Bhaktivedanta Swami Prabhupada gives the equivalent length of a yojana as about 13 km (8 mi) throughout his translations of the Bhagavata Purana. Some other traditional Indian scholars give measurements between 3 km and 6 km (4–5 miles) or thereabouts. In The Ancient Geography of India, Alexander Cunningham says that a yojana is traditionally held to be between 8 and 9 miles and calculates by comparison with Chinese units of length that it could have been between 6.7 mi (10.8 km) and 8.2 mi (13.2 km).
- Hindu cosmology
- History of measurement systems in India
- Hindu units of time
- List of numbers in Hindu scriptures
- Richard Thompson (1997), "Planetary Diameters in the Surya-Siddhanta", Journal of Scientific Exploration 11 (2): 193–200 
- O'Connor, John J.; Robertson, Edmund F., "Aryabhata I", MacTutor History of Mathematics archive, University of St Andrews.
- Srimad Bhagavatam 10.57.18 (translation) "one yojana measures about eight miles"
- Alexander Cunningham, Measures of Distance. Yojana, Li, Krosa. in The Ancient Geography of India: I. I. The Buddhist Period, Including the Campaigns of Alexander, and the Travels of Hwen-Thsang, Trübner and Company, 1871, pp. 571-574
- one Bengal mile=one coss= 2000 yards=1.8288 kilometres