GCF for 28 and 30

What is the Greatest Common Factor of 28 and 30?

Answer: GCF of 28 and 30 is 2

(Two)

Finding GCF for 28 and 30 using all factors (divisors) listing

The first method to find GCF for numbers 28 and 30 is to list all factors for both numbers and pick the highest common one:

All factors of 28: 1, 2, 4, 7, 14, 28

All factors of 30: 1, 2, 3, 5, 6, 10, 15, 30

So the Greatest Common Factor for 28 and 30 is 2

Finding GCF for 28 and 30 by Prime Factorization

The second method to find GCF for numbers 28 and 30 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 28: 2, 2, 7

All Prime Factors of 30: 2, 3, 5

As we can see there is only one Prime Factor common to both numbers. It is 2

So 2 is the Greatest Common Factor of 28 and 30

GCF Table

Number 1Number 2GCF
1330
1430
1530
1630
17301
1830
19301
2030
2130
22302
23301
2430
2530
26302
2730
2830
29301
303030
31301
32302
33303
34302
35305
36306
37301
38302
39303
403010
41301
42306

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 28 and 30? (The answer is: 2). Select the first number (e.g. '28') and the second number (e.g. '30'). 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 28 and 30?

GCF of 28 and 30 is 2