Lakh — Definition, Formula & Examples
A lakh is a unit in the South Asian numbering system equal to one hundred thousand (100,000). It is written as 1,00,000 using the Indian comma placement convention.
In the Indian numbering system, one lakh denotes the quantity . The term originates from the Hindi/Sanskrit word "lākh" and serves as a standard grouping unit in the place-value systems used across India, Pakistan, Bangladesh, Nepal, and Sri Lanka.
Key Formula
Where:
- = Ten raised to the fifth power, equal to 100,000
How It Works
In the international system, commas separate every three digits from the right (e.g., 100,000). The Indian system places the first comma after three digits, then every two digits after that. So one lakh is written 1,00,000 rather than 100,000. Larger values build on this: 10 lakhs equal 1 million, and 100 lakhs equal 1 crore (10,000,000). When reading problems from South Asian textbooks or exams, recognizing these groupings helps you convert quickly to the international format.
Worked Example
Problem: A school reports that 3.5 lakhs of books were donated. How many books is that in standard international notation?
Step 1: Recall that 1 lakh = 100,000.
Step 2: Multiply 3.5 by 100,000.
Answer: 3.5 lakhs equals 350,000 books.
Why It Matters
If you encounter math problems, news articles, or financial data from South Asia, amounts are almost always stated in lakhs and crores rather than thousands and millions. Understanding this conversion prevents misreading a value by a factor of ten or more, which matters in real-world contexts like currency exchange, population statistics, and competitive exam preparation.
Common Mistakes
Mistake: Confusing a lakh (100,000) with a million (1,000,000).
Correction: A lakh is only one-tenth of a million. To convert lakhs to millions, divide by 10: for example, 10 lakhs = 1 million.