GCF for 12 and 42

What is the Greatest Common Factor of 12 and 42?

Answer: GCF of 12 and 42 is 6

(Six)

Finding GCF for 12 and 42 using all factors (divisors) listing

The first method to find GCF for numbers 12 and 42 is to list all factors for both numbers and pick the highest common one:

All factors of 12: 1, 2, 3, 4, 6, 12

All factors of 42: 1, 2, 3, 6, 7, 14, 21, 42

So the Greatest Common Factor for 12 and 42 is 6

Finding GCF for 12 and 42 by Prime Factorization

The second method to find GCF for numbers 12 and 42 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 12: 2, 2, 3

All Prime Factors of 42: 2, 3, 7

As we can see there are Prime Factors common to both numbers: 2, 3

Now we need to multiply them to find GCF: 2 Γ— 3 = 6

GCF Table

Number 1Number 2GCF
1421
2422
3423
4422
5421
642
742
842
942
10422
11421
1242
13421
1442
1542
1642
17421
1842
19421
2042
2142
22422
2342
2442
2542
2642
2742
2842
29421
3042

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest Common Factor of 12 and 42? (The answer is: 6). Select the first number (e.g. '12') and the second number (e.g. '42'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

FAQ

What is the Greatest Common Factor of 12 and 42?

GCF of 12 and 42 is 6