GCF & LCM Calculator

Find the greatest common factor and least common multiple of two or more numbers using prime factorization.

FACTORS

LOCAL NO DATA SENT

FACTOR WORKBENCHGCF / LCM / PRIME FACTORIZATION / SHOW THE WORK

NUMBERSENTER TWO OR MORE INTEGERS

POSITIVE WHOLE NUMBERS

Separate numbers with commas, spaces, or semicolons.

ANSWER ENTER TWO OR MORE POSITIVE WHOLE NUMBERS GCF uses the prime factors every number shares. LCM uses every prime factor needed to cover all numbers.

GREATEST COMMON FACTOR—

LEAST COMMON MULTIPLE—

METHODPRIME FACTORS

INPUT COUNT2+

FACTORIZATIONBREAK EACH NUMBER INTO PRIMES

STEPSWHY THE ANSWERS WORK

READYEnter at least two positive whole numbers.

LOCAL TOOL: Your numbers and factorization walkthrough stay in your browser.

FIELD NOTE / 028

Prime factors make GCF and LCM easier to see.

The greatest common factor keeps only prime factors shared by every number. The least common multiple keeps every prime factor that appears and uses the largest exponent needed. Seeing those pieces makes the difference between GCF and LCM much easier to understand.

Prime factors make GCF and LCM easier to see.

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