# Yojana

A yojana (Devanagari: योजन; Khmer language: យោជន៍; Thai: โยชน์; Burmese: ယူဇနာ) is a measure of distance that was used in ancient India, Cambodia, Thailand and Myanmar. Various textual sources from ancient India define Yojana as ranging from 3.5 to 15 km.

## Edicts of Ashoka (3rd century BCE)

Ashoka, in his Major Rock Edict No.13, gives a distance of 600 yojanas between the Maurya empire, and "where the Yona king named Antiyoga (is ruling)", identified as King Antiochus II Theos, whose capital was Babylon. A range of estimates, for the length of a yojana, based on the ~2,000 km from Baghdad to Kandahar, on the eastern border of the empire, to the ~4,000 km to the Capital at Patna, have been offered by historians.
   ....And this (conquest) has been won repeatedly by Devanampriya both [here] and among all (his) borderers, even as far as at (the distance of) six hundred yojanas where the Yona king named Antiyoga (is ruling), and beyond this Antiyoga, (where) four kings (are ruling), (viz, the king) named Tulamaya, (the king) named Antekina, (the king) named Maka, (and the king) named Alikyashudala, (and) likewise towards the south, (where) the Cholas and Pandyas (are ruling), as far as Tamraparni.

## Yojana in geodesy

Earth's diameter and/or circumference in yojanas as mentioned by classical Hindu astronomers :
| | Diameter | Circumference |
| Aryabhata (476–550 CE) | 1,050 yojana | |
| Surya Siddhānta | | |
| Varahamihira (6th century CE) | | 3,200 yojana |
| Bhāskara I (c. 600 – c. 680 CE) | 1,050 or 1600 yojana | |
| Brahmagupta (c. 598 – c. 668 CE) | 1,581 yojana | 5,000 yojana |
| Bhāskara II (1114–1185 CE) | 1,581 yojana | 4,967 yojana |
| Nilakantha Somayaji (1444 – 1545 CE) | | 3,300 yojana |

## Hindu units of length
### Units

In Hindu scriptures, Paramāṇu is the fundamental particle and smallest unit of length.
| Measurement | Equals to... (in Hindu measurement) | Notes |
| 8 to 30 Paramāṇus | 1 trasareṇu | As per Manusmriti, one trasareṇu is the size of the smallest moving speck of dust visible to naked eye. |
| 8 trasarenu | 1 bālāgra (tip of a hair strand) | |
| 8 bālāgra | 1 likhsha (size of a nit) | |
| 8 liksha | 1 yūka (size of a louse) | |
| 8 yūka | 1 yava (width of barley grain of medium size) | |
| 8 yava | 1 aṅgula (finger-breadth) | Estimated between 1.73 cm (0.68 inches) to 1.91 cm (0.75 inches). |
| 6 finger | 1 pada (the breadth of a foot) | other sources define this unit differently: see Pada (foot) |
| 2 pada | 1 vitasti (span or distance between the tip of the forefinger and wrist) | ~ 22.86 cm (9 inches) |
| 2 vitasti | 1 hasta (cubit) | ~ 45.7 cm (18 inches) |
| 2 hasta | 1 náriká | ~ 91.5 cm (36 inches / 3 feet) |
| 2 náriká | 1 dhanu | ~ 183 cm (72 inches / 6 feet) to 192 cm ( 75.6 inches / 6 feet 3.5 inches) |
| 1 paurusa | a man's height with arms and fingers uplifted (standing reach) | ~ 192 cm (75 inches) |
| 2,000 dhanu | 1 gavyuti or gorutam (distance at which a cow's call or lowing can be heard) | ~ 3.66 to 3.84 km |
| 4 gavyuti | 1 yojana | ~ 15 kilometers |

## Variations in length

The length of the yojana varied over time and locale, its length has been estimated as:
* 13 km (8 mi) - 14th-century mathematician Paramesvara.
* 13 km (8 mi) - A. C. Bhaktivedanta Swami Prabhupada throughout his translations of the Bhagavata Purana.
* 10.8 km (6.7 mi) to 13.2 km (8.2 mi) - From The Ancient Geography of India, 1871, Alexander Cunningham, estimated by comparison with Chinese units of length.
* 8.0 km (5 mi) - 1997, Thompson, from dividing the earths diameter by the yojana circumferences offered In the Surya Siddhanta and Aryabhatiya (late 4th-century to 5th-century CE)