GCF for 45 and 80

What is the Greatest Common Factor of 45 and 80?

Answer: GCF of 45 and 80 is 5

(Five)

Finding GCF for 45 and 80 using all factors (divisors) listing

The first method to find GCF for numbers 45 and 80 is to list all factors for both numbers and pick the highest common one:

All factors of 45: 1, 3, 5, 9, 15, 45

All factors of 80: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80

So the Greatest Common Factor for 45 and 80 is 5

Finding GCF for 45 and 80 by Prime Factorization

The second method to find GCF for numbers 45 and 80 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 45: 3, 3, 5

All Prime Factors of 80: 2, 2, 2, 2, 5

As we can see there is only one Prime Factor common to both numbers. It is 5

So 5 is the Greatest Common Factor of 45 and 80

GCF Table

Number 1Number 2GCF
3080
31801
3280
33801
34802
35805
3680
37801
38802
39801
4080
41801
42802
43801
44804
4580
46802
47801
4880
49801
5080
51801
52804
53801
54802
5580
5680
57801
58802
59801

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 45 and 80? (The answer is: 5). Select the first number (e.g. '45') and the second number (e.g. '80'). 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 45 and 80?

GCF of 45 and 80 is 5