A lakh (/læk, lɑːk/; abbreviated L; sometimes written Lac or Lacs) is a unit in the Indian numbering system equal to one hundred thousand (100,000; scientific notation: 105). In the Indian convention of digit grouping, it is written as 1,00,000. For example, in India 150,000 rupees becomes 1.5 lakh rupees, written as ₹1,50,000 or INR 1,50,000.
It is widely used both in official and other contexts in Bangladesh, Bhutan, India, Myanmar, Nepal, Pakistan, and Sri Lanka. It is often used in Indian, Pakistani, and Sri Lankan English. In Pakistan, the word lakh is used mostly in local languages rather than in English media.
In Indian English, the word is used both as an attributive and non-attributive noun, and with either a marked ("-s") or unmarked plural, as in: "1 lakh people" or "1 lakh of people"; "200 lakh rupees"; "5 lakh of rupees"; "rupees 10 lakhs"; or "5 lakhs of rupees". In the abbreviated form, usage such as "₹5L" (for "rupees 5 lakhs") is common. In this system of numeration 100 lakh is called one crore and is equal to 10 million.
In colloquial Urdu, especially in the city of Karachi, the word peti ("suitcase") is also used to denote one lakh rupees. This originated during the General Zia era, when the largest denomination of currency was the 100 rupee note, and one lakh rupees would fill a small suitcase (peti as in Bombay Hindi). Hence, even after the Zia era, one peti has continued to mean one lakh rupees.
The word lakhi is commonly used throughout Tanzania to denote 100,000 shillings and is likely to have entered the Swahili language from Indian and Pakistani immigrants.
The root of the word lakh might be the Pali lakkha (masculine noun, "mark, target, stake in gambling"), from which the numerical meaning, "one hundred thousand" is derived. Another possible root could be the Sanskrit laksha (Devanagari: लक्ष lakṣa), which has similar meanings in that language.
Prefixes for Naming Multiples and Submultiples of Units: […] The prefix "myria" is sometimes used for 104 and "lakh" for 105.
lakṣá10881 lakṣá masculine ʻ stake, prize ʼ R̥gveda, ʻ mark, sign ʼ Mahābhārata, ʻ 100,000 ʼ Yājñavalkya, ʻ aim ʼ Kālidāsa, lakṣya— neuter, masculine ʻ aim ʼ Muṇḍ Upaniṣad, ʻ prize ʼ Mahābhārata, ʻ 100,000 ʼ Mahābhārata, . [√lakṣ. For derivation from root to become numeral, see Addenda: Pali lakkha— masculine ʻ mark, target, stake in gambling ʼ; Oṛiyā lākha, nākha ʻ aim, distinguishing mark ʼ, lācha ʻ brand ʼ; Gujarātī lāchɔ masculine ʻ burning the feet ʼ; Marāṭhī lās masculine ʻ mark made by cautery ʼ, neuter.]