Fraction Calculator

Add, subtract, multiply, and divide fractions.

How to Do It Manually

Fraction arithmetic follows specific rules for each operation. Always simplify the result by dividing numerator and denominator by their greatest common divisor (GCD).

  1. Addition/Subtraction: Find the least common denominator (LCD), convert fractions, then add/subtract numerators.
  2. Multiplication: Multiply numerators together and denominators together.
  3. Division: Flip the second fraction (take its reciprocal), then multiply.
  4. Simplify: Divide numerator and denominator by their GCD.

Frequently Asked Questions

How do I find the least common denominator?

The LCD is the least common multiple (LCM) of the denominators. Find the LCM by listing multiples or using prime factorization.

How do I simplify a fraction?

Find the GCD of numerator and denominator, then divide both by it. Example: 12/18 → GCD is 6 → 2/3.