Before the introduction of the metric system, one may divide the history of Indian systems of measurement into three main periods: the pre-Akbar period, the period of the Akbar system, and the British colonial period.
During the pre-Akbar period, weights and measure systems varied from region to region, commodity to commodity, and rural to urban areas. The weights were based on the weight of various seeds (in particular the wheat berry and Ratti) and lengths were based on the length of arms and width of fingers. During his reign, the Mughal emperor Akbar realized a need for a uniform system, and used the weight of the barley corn as a standard. This did not replace the existing system; rather, it simply added another system of measurement.
When the British first began trading in India, they accepted barley corn as a unit for weighing gold. Eventually, the British introduced their own system for weighing gold. In 1956, the government of independent India passed the Standards of Weights Act, which would come into effect in 1958. The metric system was made mandatory for weights in October 1960, and for measures in April 1962.
Conversion
In 1956, for metrication, the Indian government defined the Standards of Measurements Act (No. 89 of 1956, amended 1960, 1964) as follows:
These are the weights and measures popular in North India before the adoption of the metric system. There were different systems in Bengal, the Presidency of Madras, and Bombay. The following nomenclature was prevalent in North India until the metric system was established:
4 Chāwal (grain of rice) = 1 Dhan (weight of one wheat berry)
Grains were not weighed. Special hour-glass shaped measure were used to determine the volume.
Smallest unit = 1 Nilve
2 Nilve = 1 Kolve
2 Kolve = 1 Chipte (about quarter litre)
2 Chipte = 1 Mapte (about half litre)
2 Mapte = 1 Ser (about one litre)
Liquid Volume Measures
These were hour glass shaped measure used for Milk, Ghee, Oils. The bottom was round like an inverted dome, the top was like flared rim. This shape helped in pouring the liquids.
4 Chhataank = 1 Pav
4 Pav = 1 Seer
40 Seer = 1 Maund
Length Measure
Measure of length is Gaz. To interpret Gaz, depends on what one is measuring and where they are. Bengal: 36", Bombay: 27", Madras: 33", Government Average: 33". The hand measurements were used.
Anguli (width of 3 fingers) = 1 Girah
8 Girah = 1 Hath (elbow to the end of the middle finger, approximately 18" )
Akbar standardised weights and measurements using a barley corn (Jau). For weights, he used the weight of a Jau, while the width of a Jau set the standard for length.
1. Length: Ilahi Gaz (33 to 34 inches or 840 to 860 millimetres); 1 Gaz = 16 Grehs; 1 Greh = 2 pais
At the time of Shah Jahan there existed three different Gaz:[1]
Indian System
Metric System
Shahi gaz
101.6 cm
Shahijahani/Lashkari
95.85 cm
Aleppo gaz
67.73 cm
a) Shahi gaz = 101.6 cm
b) Shahijahani or Lashkari = 95.85 cm
c) Aleppo gaz = 67.73 cm
2. Commodity weight: Ser = 637.74 grams
3. Commodity Spices: The Dam was a copper coin used as a weight as well as currency. 1 Dam = 20 grams
From 1833 the rupee and tolā weight was fixed at 180 grains, i.e. 11.66382 grams. Hence the weight of 1 maund increased to 37.324224 kilogram.[3]
Traditionally one maund represented the weight unit for goods which could be carried over some distance by porters or pack animals.
^Hobson-Jobson: A Glossary of Colloquial Anglo-Indian Words and Phrases, and Kindred Terms, Etymological, Historical, Geographical and Discursive by Col. Henry Yule and A.C. Burnell, Originally published 1903, Reprint, 1968
Prinsep, James (editor Edward Thomas): Essays on Indian Antqities, Historic, Numismatic, and Palaeographic, of the late James Prinsep, F.R.S., to which are added his Useful Tables illustrative of Indian History, Chronology, Modern Coinages, Weights, Measures etc. Two Volumes, Reprint, Indological Book House, Delhi and Varanasi, 1971. Originally published in London, 1858.