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➗ GCD / LCM Calculator
GCD (Greatest Common Divisor, a.k.a. GCF) is the largest number dividing all inputs. LCM (Least Common Multiple) is the smallest number that all inputs divide. Enter 2 or more integers — we compute both, plus show prime factorizations.
Examples
48, 60GCD = 12 · LCM = 24012, 18, 24GCD = 6 · LCM = 72482⁴ × 3Frequently asked questions
What is GCD used for?
Simplifying fractions (divide both numerator and denominator by GCD). Modular arithmetic, RSA cryptography, scheduling problems.
What is LCM used for?
Adding fractions with different denominators (common denominator = LCM). Repeating-event scheduling (e.g., two events every 4 and 6 days coincide every LCM(4,6)=12 days).
GCD vs GCF — different?
No, identical — GCD (Greatest Common Divisor) and GCF (Greatest Common Factor) are the same thing.
Why are they always non-negative?
By convention we take absolute values first. GCD(−12, 18) = 6, same as GCD(12, 18).
About this tool
GCD / LCM Calculator runs entirely in your browser using standard Web APIs. No data is sent to any server. The source for this tool is in our public GitHub repository.
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- 🔢 Number Base Converter — Convert between binary, octal, decimal, and hexadecimal.
Why this tool
vs typical free web-tool sites
| 1vw | Typical free site | |
|---|---|---|
| Price | Free | Free |
| Signup required | No | Often (for premium features) |
| Ads inside the tool | No | Yes (banner + video) |
| Data sent to server | No (browser-only) | Yes (inputs analyzed for ads) |
| Total tools | 96 | Often <20 or scattered across sites |
| Bookmarkable URL per tool | Yes | Mixed |
| Loads in under 1s | Yes (static) | Often slow (ad tracking) |
| Multilingual | EN / ES / PT / FR / DE | Usually EN only |
| Open source | Yes | No |