LCM & HCF Calculator
LCM and HCF (GCD) of two or more numbers, with prime factorisation of each number.
Result
How to use
- 1
Type two or more whole numbers.
- 2
See the HCF and LCM with the prime factorisation of every number.
- 3
Use the working shown to check your homework.
Questions
What is the difference between HCF and LCM?
HCF (also called GCD) is the largest number that divides all the numbers exactly. LCM is the smallest number that all of them divide into exactly.
How are they found using prime factors?
Write each number as a product of primes. HCF multiplies the common primes with their lowest powers; LCM multiplies every prime with its highest power.
Is HCF × LCM = product of the numbers?
Only for two numbers. For 12 and 18: HCF 6 × LCM 36 = 216 = 12 × 18. It does not hold for three or more numbers.
About this LCM & HCF tool
LCM & HCF Calculator — LCM and HCF (GCD) of two or more numbers, with prime factorisation of each number. It is one of 200 free tools on namasivayam.in, made by software engineer Namasivayam Vadivelan for everyday use in India.
Everything is calculated instantly in your browser: nothing you type or upload is sent to any server, there is no sign-up, and it works on mobile and desktop. Type two or more whole numbers.
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Results are estimates to help you plan. They are not financial, tax or medical advice.