➗ GCF & LCM Calculator

What is GCF & LCM Calculator?

The GCF & LCM Calculator finds the greatest common factor (GCF) and least common multiple (LCM) of two, three or four numbers in one go. Type up to four positive whole numbers, leave any extras blank, and the tool runs the Euclidean algorithm to return both results instantly, then cross-checks them with a full prime-factorization breakdown of every input so you can follow the math step by step. It handles large numbers without overflow by dividing before multiplying, which keeps fraction work, denominators and ratio problems accurate. Everything is computed locally in your browser with no account and no data upload.

How to Use GCF & LCM Calculator

1. Enter two, three or four positive whole numbers (blank fields are ignored)
2. Read the greatest common factor and least common multiple results
3. Scan the prime-factorization breakdown to verify each step by hand

Why Use Our GCF & LCM Calculator?

• GCF and LCM for any 2, 3 or 4 numbers — leave unused fields empty
• Euclidean-algorithm core with prime-factorization rows for every input
• Large-number safe by dividing before multiplying so nothing overflows
• 100 percent in-browser calculation with no sign-up or data leaving your device

Common Use Cases

• Simplifying fractions to lowest terms with the GCF
• Finding a common denominator to add or subtract fractions
• Solving ratios, gear, tile or scheduling problems that need a shared unit

Frequently Asked Questions

• What is the difference between GCF and LCM?▾
  The GCF (greatest common factor) is the largest whole number that divides every value in the set, while the LCM (least common multiple) is the smallest whole number that every value divides into evenly. For 12 and 18 the GCF is 6 and the LCM is 36.
• Does it work with 3 or 4 numbers?▾
  Yes. Leave any extra input blank to compute for 2, 3 or all 4 numbers, and the tool reports the GCF and LCM for exactly the values you filled in.
• Where are GCF and LCM used in real life?▾
  They are the core of working with fractions: the GCF simplifies fractions to lowest terms and the LCM finds the common denominator when adding or subtracting fractions with different bottoms.