Enter two or more whole numbers.
Formula
GCD × LCM = a × b (for two numbers)
Worked example
For 12, 18 and 30: GCD = 6 and LCM = 180.
Frequently asked questions
What is the GCD used for?
Simplifying fractions: divide top and bottom by the GCD.
What is the LCM used for?
Finding a common denominator, or when repeating events coincide.
How do prime factors help?
The GCD uses common factors with the lowest powers; the LCM uses all factors with the highest powers.
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Results are estimates for information only. Check important figures with a professional.