GCD & LCM calculator
Find the greatest common divisor and least common multiple of any set of numbers.
How to use
- Enter two or more positive whole numbers, separated by spaces, commas or line breaks.
- Read the GCD and LCM in the result pane — both update as you type.
- Copy the result for your homework or schedule planning.
Frequently asked questions
How many numbers can I enter?
Any amount — GCD and LCM are computed across the whole set, not just pairs.
What is the difference between GCD and LCM?
GCD is the largest number that divides all inputs evenly (useful for splitting into equal groups); LCM is the smallest number every input divides into (useful for synchronising cycles).
Why are zero and negative numbers rejected?
FPB and KPK are defined for positive integers in school mathematics; allowing zero would make LCM degenerate to zero.
About this tool
The greatest common divisor (GCD, known as FPB in Indonesian schools) and least common multiple (LCM/KPK) appear everywhere from primary-school homework to real scheduling problems: simplifying fractions, splitting items into equal groups, or finding when two repeating events coincide — buses that depart every 12 and every 18 minutes meet every 36. Enter two or more positive whole numbers separated by spaces, commas or new lines and both results appear at once. The calculation uses exact big-integer arithmetic, so even very large numbers produce correct results rather than floating-point approximations.