CalcLive

    Common Factor Calculator Online Free

    Common Factor Calculator

    Find all common factors and the Greatest Common Factor (GCF) of multiple integers

    Common Factor Calculator

    Enter integers separated by commas to find their common factors

    Results will be calculated automatically as you type

    How to Use

    What are Common Factors?

    Common factors are numbers that divide two or more integers evenly (without remainder). The Greatest Common Factor (GCF), also called the Greatest Common Divisor (GCD), is the largest of these common factors.

    Understanding the Results

    • GCF: The largest number that divides all input numbers evenly
    • Common Factors: All numbers (including GCF) that divide all inputs evenly
    • Individual Factors: All divisors of each number (common factors highlighted in blue)
    • Factor Count: Shows total factors and how many are common to all numbers

    💡 Quick Examples

    • 12, 18: Common factors are 1, 2, 3, 6 → GCF = 6
    • 24, 36, 48: Common factors are 1, 2, 3, 4, 6, 12 → GCF = 12
    • 15, 28: Common factor is 1 only → GCF = 1 (coprime numbers)
    • 100, 50: Common factors are 1, 2, 5, 10, 25, 50 → GCF = 50

    The common factor calculator lists all factors shared by two or more integers. Enter your numbers to see every common divisor and identify the greatest common factor (GCF). Use it to simplify fractions, solve ratio problems, and check divisibility.

    See also:

    Greatest Common Factor Calculator →Least Common Multiple Calculator →Prime Factorization Calculator →

    How Common Factors Are Found

    First, list all factors of each number by finding every integer that divides it evenly. Then identify the values that appear in every list — these are the common factors. The largest of these is the greatest common factor. For large numbers, prime factorization is more efficient than listing all factors.

    Factors of 12: 1, 2, 3, 4, 6, 12 Factors of 18: 1, 2, 3, 6, 9, 18 Common factors: 1, 2, 3, 6 GCF = 6

    Frequently Asked Questions

    What is a common factor?⌄

    A common factor of two or more numbers is an integer that divides each of them without a remainder. Every set of positive integers shares at least the common factor 1.

    How do I use common factors to simplify a fraction?⌄

    Divide both the numerator and denominator by their greatest common factor. For example, 12/18 simplifies to 2/3 because the GCF is 6.

    Browse all Math Calculators →