What does this tool do?
This tool instantly computes the least common multiple (LCM) and greatest common divisor (GCD) of a list of numbers. Enter two or more integers to simplify fractions, synchronize periodic events, or find common denominators.
How to use it
- Enter your values into the fields.
- The result is calculated instantly.
- Read or copy the result.
How it works
It first finds the GCD of two numbers using the Euclidean algorithm: divide the larger by the smaller and repeat with the remainder until it reaches zero. The LCM is then derived from a×b/GCD(a,b). For a list, the operation folds pairwise — (a,b), then ((a,b),c), and so on.
Common use cases
It is ideal for finding a common denominator when adding fractions, working out when timers of different periods coincide, and matching gear or chain ratios. Students use it to check homework, while developers plan repeating intervals such as cron-like schedules.
Frequently asked questions
Can I enter more than two numbers?
Yes — type as many integers as you like separated by commas or spaces, and both the LCM and GCD are computed iteratively across the whole list.
Are negative numbers or zero allowed?
Signs are ignored and absolute values are used for the GCD; because the LCM is undefined when a list contains zero, you should enter non-zero values.
Is LCM & GCD Calculator free?
Yes. LCM & GCD Calculator and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. LCM & GCD Calculator works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.