LCM and GCF Calculator
The GCF is the largest number that divides all your values; the LCM is the smallest number they all divide into. Enter two or more whole numbers to get both at once.
Your numbers
Result
- Count
- 2
| Item | Value |
|---|---|
| Numbers | 12, 18 |
| GCF (greatest common factor) | 6 |
| LCM (least common multiple) | 36 |
GCF and LCM explained
The greatest common factor (GCF, also GCD) of 12 and 18 is 6 — the biggest number dividing both. The least common multiple (LCM) is 36 — the smallest number both divide into. A handy check: for two numbers, GCF x LCM = a x b (6 x 36 = 12 x 18).
Where they are used
The GCF simplifies fractions (divide top and bottom by it) and splits things into equal groups. The LCM finds a common denominator when adding fractions and lines up repeating cycles — like when two events on different schedules coincide.
Frequently asked questions
Sources
- Number theory — LCM and GCF (Euclidean algorithm)
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