About this tool
Find the greatest common factor and least common multiple of two or more whole numbers.
The GCF uses Euclid’s algorithm repeatedly. LCM(a, b) = |a × b| ÷ GCF(a, b), applied across the list.
Formula: lcm(a,b) = |ab| / gcd(a,b)
Example: Numbers (separated by commas, spaces or new lines) = 12, 18, 30 → Greatest common factor = 6, Least common multiple = 180.
Whole numbers only. Very large LCMs are shown in full digits.
Quick steps
- Enter your values — every field shows its unit.
- Press Calculate (or Try an example to see how it works).
- Read the results and copy them if you need them elsewhere.
The calculation runs in your browser. Nothing you type is sent to 1CLIK.
FAQ
How does the GCF & LCM Calculator work?
The GCF uses Euclid’s algorithm repeatedly. LCM(a, b) = |a × b| ÷ GCF(a, b), applied across the list.
What should I keep in mind?
Whole numbers only. Very large LCMs are shown in full digits.
Is my data sent anywhere?
No. The numbers stay on your device; the page only shows the result.