Sri Lankan units of measurement
A number of different units of measurement were used in Sri Lanka to measure quantities like length, mass and capacity. Under the British Empire, imperial units became the official units of measurement and remained so until Sri Lanka adopted the metric system in the 1970s.
One covid was equal to 0.464 m (18.5 in). The bamba, still in use in 2010, is the distance between a man's outstretched arms. Units used in measuring road distances included the gavva and yoduna (plurals gavu and yojana - a yoduna was 4 gavu) and the hoo kiyana dura.
Area was often measured in terms of the land that could be sown with a specific amount of seed or rice, including the pala, amuna (4 pala) and kiriya (4 amunas) and the riyana. In one region, a kiriya was about 8 acres.
Small weights could be measured in seeds, such as the tala, amu, vee ata (3 amu), madati (8 vee ata), majadi, maditi, kalanda and manjadi.
Different units were used for liquid and dry capacity.
Another source suggests that a seer was equal to 1.86 imperial pints or 1.06 litres. 
One ammonam was equal to 203.4 l. Some other units are provided below:
1 parrah = 1/8 ammonam
1 seer = 1/288 ammonam.
The chundoo was equal to nearly half a pint.
Maccauly stated in 1818 that to the north of Colombo an Ammonam contained 16 Parahs, and 2.5 Ammonams equalled one Acre, but that to the south there were 8 Parahs to the Ammonam. He describes the Parah as a measure 16.7 inches wide and 5.6 inches deep.
Montgomery, writing in 1835, describes the interior measurement of a Parrah as a perfect cube of 11.571 inches, and the seer as a cylinder of depth 4.35 inches and diameter 4.35 inches.
- Washburn, E.W. (1926). International Critical Tables of Numerical Data, Physics, Chemistry and Technology. New York: McGraw-Hil Book Company, Inc. p. 4.
- Clarke, F.W. (1891). Weights Measures and Money of All Nations. New York: D. Appleton & Company. p. 23.
- "History". Measurement Units and Services Department. Measurement Units and Services Department. Retrieved 2 January 2015.
- Cardarelli, F. (2003). Encyclopaedia of Scientific Units, Weights and Measures. Their SI Equivalences and Origins. London: Springer. p. 7. ISBN 978-1-4471-1122-1.
- Pieris, Kamalika. "Weights and measures in ancient and medieval Sri Lanka". Daily News (Sri Lanka). Retrieved 3 January 2015.
- Prinsep, James (1840). Useful tables, forming an appendix to the Journal of the Asiatic Society: part the first, Coins, weights, and measures of British India. Bishop's College Press. Retrieved 2 January 2015.
- Maccauly, Thomas (1818). The Indian Trader's complete Guide, being a correct account of coins, weights,measures &c. &c. at the different settlements of India and adjacent native sovereignties of Asia. Calcutta. p. 42. Retrieved 2 January 2015.
- "Seer". Sizes, grades, units, scales, calendars, chronologies. Retrieved 2 January 2015.
- Montgomery, Martin (1835). "Ceylon". History of the British colonies: Vol 1: Possessions in Asia (2nd ed.). Cochrane. p. 561. Retrieved 2 January 2015.