LCM & GCD Calculator interactive tool
Enter integers
You can paste a list like 6 9 15 or 6,9,15. The calculator will ignore empty entries.
LCM & GCD
For numbers 12, 18, 30:
GCD (greatest common divisor)6
GCD is the largest integer that divides all the numbers with no remainder.
LCM (least common multiple)180
LCM is the smallest positive integer that is a multiple of all the given numbers.
What Is LCM & GCD?
An LCM & GCD calculator finds two foundational quantities for a list of integers: the greatest common divisor (GCD) and the least common multiple (LCM). These appear everywhere in fraction problems and divisibility exercises.
Greatest Common Divisor vs. Least Common Multiple
- GCD: The largest integer that divides all the numbers with no remainder.
- LCM: The smallest positive integer that is a multiple of all the numbers.
This LCM and GCD calculator uses efficient algorithms under the hood but presents the results in a simple, readable way, making it ideal for middle school and high school math practice.
How To Use the LCM & GCD Calculator
- Enter two or more integers separated by commas or spaces in the input box.
- Make sure all entries are whole numbers; the LCM and GCD calculator will ignore any blank values.
- Review the greatest common divisor (GCD) for your list of numbers in the results card.
- Review the least common multiple (LCM) shown beneath the GCD to understand the smallest shared multiple.
- Use the Example button to load a common classroom example, or Reset to clear the list and paste your own numbers.