GCF and LCM Calculator
Enter your numbers and see the LCM, the GCF and the prime factorization of each one.
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| LCM (least common multiple) | 180 |
| GCF (greatest common factor) | 6 |
Prime factorization
- 12 = 2² × 3
- 18 = 2 × 3²
- 30 = 2 × 3 × 5
Quick answer: To find the GCF and LCM, enter two or more numbers separated by spaces or commas. The calculator shows the least common multiple, the greatest common factor (also called GCD) and each prime factorization so you can check the work.
How to do it in 3 steps
- 1Enter the numbers.
- 2See the LCM and GCF.
- 3Check the prime factorization.
Why use Pronto Arquivo
Several numbers
Works with 2, 3 or more numbers at once.
Prime factorization
Shows how each number breaks down, like 12 = 2² × 3.
For fractions
The LCM of the denominators is the least common denominator.
Fast
Results appear as you type.
Guides
How to find the LCM with prime factors
Factor each number and multiply every prime using its highest exponent. For the GCF, multiply only the shared primes using their lowest exponent.
Frequently asked questions
What is the LCM?
The smallest number that is a multiple of all the given numbers. LCM(4, 6) = 12.
What is the GCF?
The largest number that divides all the given numbers. GCF(12, 18) = 6.
How are LCM and GCF related?
For two numbers, LCM × GCF = a × b.
Does it work with large numbers?
Yes, up to 1 billion.
