Common Factor Calculator - Find All Common Factors

Find all common factors of 2-3 numbers including GCF and factor pairs with instant, accurate results

Updated: November 2025 • Free Tool

Common Factor Calculator

Results

Greatest Common Factor (GCF)
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All Common Factors
Enter numbers and click Calculate

What is a Common Factor Calculator?

A Common Factor Calculator is a free mathematical tool that finds all factors shared between 2 or 3 numbers. Unlike calculators that only show the Greatest Common Factor (GCF), this tool displays the complete list of all common factors, their pairs, and individual factor breakdowns.

This calculator is perfect for:

  • Students - Understanding factor relationships and solving homework problems
  • Teachers - Demonstrating factor concepts with visual examples
  • Math Enthusiasts - Analyzing number properties and relationships

For finding all factors of a single number, use our Factor Calculator to identify all divisors and factor pairs.

To break down numbers into prime factors, explore our Prime Factorization Calculator for exponential notation and factor trees.

For finding just the largest shared factor, check out our Greatest Common Factor Calculator to quickly determine the GCF of multiple numbers.

How Common Factor Calculation Works

The calculator uses a systematic algorithm to find all common factors:

Step 1: Find Individual Factors

Identify all factors of each number by testing divisors from 1 to the square root of each number.

Step 2: Find Intersection

Compare all factor sets and identify numbers that appear in every set. These are the common factors.

Step 3: Identify GCF

The largest number in the common factors set is the Greatest Common Factor (GCF).

Step 4: Generate Factor Pairs

Create pairs of common factors that multiply to give values relevant to the original numbers.

Example: For 24 and 36:
  • Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
  • Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36
  • Common Factors: 1, 2, 3, 4, 6, 12
  • GCF: 12

Key Common Factor Concepts

Common Factor

A number that divides evenly into two or more numbers without leaving a remainder.

GCF (Greatest Common Factor)

The largest common factor shared by all numbers. Also called GCD (Greatest Common Divisor).

Factor Pair

Two numbers that multiply together to produce a given result. Common factor pairs use shared factors.

Coprime Numbers

Numbers whose only common factor is 1. Their GCF is 1 (e.g., 8 and 15).

How to Use This Calculator

1

Select Number Count

Choose whether to find common factors of 2 or 3 numbers

2

Enter Numbers

Input positive integers in each field

3

Click Calculate

Get instant results with all common factors

4

View Results

See GCF, complete list, and factor pairs

Benefits of Using This Calculator

  • Complete Factor List: See ALL common factors, not just the GCF, for comprehensive understanding.
  • Instant Results: Get accurate calculations immediately without manual computation.
  • Educational Tool: Perfect for learning factor relationships and verifying homework solutions.
  • Factor Pairs Display: Understand multiplicative relationships between common factors.
  • Multiple Numbers Support: Find common factors of 2 or 3 numbers simultaneously.
  • Individual Factor Breakdown: See all factors of each number separately for comparison.

Common Applications

1. Fraction Simplification

Find the GCF to reduce fractions to their simplest form by dividing numerator and denominator by the GCF.

2. Problem Solving

Distribute items equally into groups, divide areas into equal sections, or solve optimization problems.

3. Pattern Recognition

Identify cyclic patterns and periodic events that occur at regular intervals.

4. Algebraic Simplification

Factor out common terms in polynomials and algebraic expressions using the GCF.

For finding the smallest common multiple instead, use our Least Common Multiple Calculator to determine when events coincide or find common denominators.

To perform long division with remainders and quotients, try our Long Division Calculator for step-by-step division solutions.

Common Factor Calculator - Free online tool to find all common factors of 2-3 numbers including GCF and factor pairs
Professional common factor calculator interface for finding all shared factors between multiple numbers. Features include complete factor lists, GCF display, factor pairs, and individual factor breakdowns.

Frequently Asked Questions (FAQ)

Q: What are common factors?

A: Common factors are numbers that divide evenly into two or more numbers without leaving a remainder. For example, the common factors of 12 and 18 are 1, 2, 3, and 6.

Q: How do you find all common factors?

A: First, find all factors of each number. Then, identify which factors appear in all sets. These shared factors are the common factors. The largest one is the GCF (Greatest Common Factor).

Q: What is the difference between GCF and common factors?

A: Common factors are all numbers that divide evenly into the given numbers. The GCF (Greatest Common Factor) is the largest number among all common factors.

Q: Can I find common factors of three numbers?

A: Yes, this calculator can find common factors of 2 or 3 numbers. Simply enter all numbers and it will show all factors that divide evenly into every number entered.