Can I enter negative numbers or zeros?

Yes. The calculator uses absolute values for LCM/GCF. Zeros are allowed: gcd(a,0)=|a| and lcm(0,n)=0.

Does it work for many numbers?

Yes. LCM and GCF are computed by reducing the whole list pairwise.

Will it handle very large integers?

If inputs exceed JavaScript's safe integer range, the tool automatically switches to BigInt arithmetic.

LCM & GCF Calculator (Least Common Multiple, Greatest Common Factor)

LCM & GCF Calculator – Least Common Multiple & Greatest Common Factor

Enter integers separated by commas, spaces, or new lines. We’ll compute the least common multiple (LCM) and greatest common factor (GCF/HCF) for the whole list.

Enter integers:

Show Euclidean steps Use absolute values

Notes: LCM is reported as non-negative. If any input exceeds 9,007,199,254,740,991 (2⁵³−1), the calculator switches to BigInt mode automatically.

Results will appear here.

How It Works

We use the Euclidean Algorithm for GCF/HCF and the identity \( \text{LCM}(a,b) = \dfrac{|a \cdot b|}{\text{GCF}(a,b)} \). For many numbers \(a_1,\dots,a_n\), we reduce pairwise: \( \text{GCF}(a_1,\dots,a_n) = \text{GCF}(\dots\text{GCF}(a_1,a_2),\dots,a_n) \) and \( \text{LCM}(a_1,\dots,a_n) = \text{LCM}(\dots\text{LCM}(a_1,a_2),\dots,a_n) \).

Zeros: \( \gcd(a,0)=|a| \); \( \operatorname{lcm}(0,n)=0 \) if any input is zero.
Negatives: Signs don’t matter for final results; we use absolute values.
Large integers: When needed, we switch to precise BigInt arithmetic.

Frequently Asked Questions

Which separators can I use?

Commas, spaces, or new lines. Extra whitespace is ignored.

Can I enter negative numbers or zero?

Yes. We use absolute values for GCF/LCM. Zeros are allowed; if any number is zero, the LCM of the list is zero.

What if I enter only one number?

Then GCF = |n| and LCM = |n|.

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