LCM for 12 and 42

What's the Least Common Multiple (LCM) of 12 and 42?

Answer: LCM of 12 and 42 is 84

(Eighty-four)

Finding LCM for 12 and 42 using GCF's of these numbers

The first method to find LCM for numbers 12 and 42 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 12 and 42 is 6, so

LCM = (12 × 42) ÷ 6

LCM = 504 ÷ 6

LCM = 84

Finding LCM for 12 and 42 by Listing Multiples

The second method to find LCM for numbers 12 and 42 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 12: 12, 24, 36, 48, 60, 72, 84, 96, 108

Multiples of 42: 42, 84, 126, 168

So the LCM for 12 and 42 is 84

Finding LCM for 12 and 42 by Prime Factorization

Another method to find LCM for numbers 12 and 42 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 12: 2, 2, 3 (exponent form: 22, 31)

All Prime Factors of 42: 2, 3, 7 (exponent form: 21, 31, 71)

22 × 31 × 71 = 84

See Also

About "Least Common Multiple" Calculator

This calculator will help you find the Least Common Multiple (LCM) of two numbers. For example, it can help you find out what's the Least Common Multiple (LCM) of 12 and 42? (The answer is: 84). Select the first number (e.g. '12') and the second number (e.g. '42'). After that hit the 'Calculate' button.
Least Common Multiple (LCM) also known as the Lowest Common Multiple or Smallest Common Multiple of 2 numbers - it is the smallest positive integer that is divisible by both numbers

LCM Table

Number 1Number 2LCM
14242
24242
34242
44284
542210
642
74242
842168
942126
1042210
1142462
1242
1342546
1442
1542210
1642
1742714
1842
1942798
2042420
2142
2242462
2342966
2442
25421050
2642546
2742
2842
29421218
3042

FAQ

What's the Least Common Multiple (LCM) of 12 and 42?

LCM of 12 and 42 is 84