LCM and GCF Calculator
Find the least common multiple (LCM) and greatest common factor (GCF) of two or more numbers with this free online calculator, with prime factorization.
Found it useful? Share LCM and GCF Calculator
Free, no sign-up, works in the browser — send it to a friend or add it to your site.
Related tools
- Prime Factorization CalculatorFind the prime factorization of any number with steps, check if a number is prime, list all divisors and prime numbers. Free online prime factor calculator.
- Anniversary Gift FinderFind the traditional and modern wedding anniversary gift, gemstone, and flower for any year instantly with this free online anniversary gift finder.
- Cat Years CalculatorConvert cat years to human years with the vet age formula and AAFP/ICatCare life stage. Free online cat age calculator, indoor vs outdoor lifespan.
- Exponent CalculatorCalculate powers and exponents with this free online exponent calculator: exact big numbers like 2^100, negative exponents as fractions and fractional powers.
- Fraction CalculatorAdd, subtract, multiply and divide fractions and mixed numbers online free with steps. Free online fraction calculator that simplifies and converts decimals.
- GPA CalculatorCalculate your GPA online free on the 4.0 scale: semester, weighted (Honors/AP) and cumulative GPA with credit hours. Free online GPA calculator.
Part of the toolkit
How to use LCM and GCF Calculator
- 1Type two or more whole numbers separated by commas or spaces
- 2Read the GCF (GCD) and LCM instantly, with each number's prime factorization
- 3Copy the result or try an example
Frequently asked questions
How do you find the LCM of 12, 18 and 30?▾
Factor each: 12 = 2² × 3, 18 = 2 × 3², 30 = 2 × 3 × 5. Take every prime at its highest power: 2² × 3² × 5 = 180.
How do you find the GCF?▾
Multiply the primes all numbers share, at their lowest power. For 12, 18 and 30 only 2 and 3 are shared, so the GCF is 2 × 3 = 6.
Are GCF, GCD and HCF the same?▾
Yes — greatest common factor, greatest common divisor and highest common factor are three names for the same number.
How are LCM and GCF related?▾
For two numbers, LCM × GCF = a × b. For 8 and 12: GCF 4 × LCM 24 = 96 = 8 × 12.
What is the lowest common denominator?▾
The LCM of the denominators. To add 1/12 + 1/18, use 36, the LCM of 12 and 18.
Embed LCM and GCF Calculator on your website▾
Paste this snippet into your page. The embedded tool runs in your visitor's browser and shows a small “Powered by clkr.work” link.