LCM & HCF Step-by-Step Calculator
Visual prime factorisation trees · Full working shown · Perfect for Class 4–8
Enter Your Numbers
Input 2 to 4 numbers (between 2 and 1000) to find their LCM and HCF
Number 1:
Number 2:
Try these examples:
📚 Understanding LCM & HCF
🔽 HCF (Highest Common Factor)
The largest number that divides all given numbers exactly.
Example: HCF of 12 and 18 is 6
12 ÷ 6 = 2, 18 ÷ 6 = 3
12 ÷ 6 = 2, 18 ÷ 6 = 3
🔼 LCM (Lowest Common Multiple)
The smallest number that is a multiple of all given numbers.
Example: LCM of 12 and 18 is 36
36 = 12 × 3 = 18 × 2
36 = 12 × 3 = 18 × 2
🌳 Prime Factorisation
Breaking down a number into a product of prime numbers only.
Example: 12 = 2² × 3
18 = 2 × 3²
18 = 2 × 3²
🎯 The Method
HCF: Minimum powers of common primes
LCM: Maximum powers of all primes
For 12 and 18:
HCF = 2¹ × 3¹ = 6
LCM = 2² × 3² = 36
HCF = 2¹ × 3¹ = 6
LCM = 2² × 3² = 36