Fraction Calculator

Add, subtract, multiply or divide two fractions and get the result in lowest terms, as a mixed number and as a decimal.

How to use the Fraction Calculator

  1. Enter the numerator and denominator of the first fraction.
  2. Choose the operation, then enter the second fraction.
  3. Read the simplified answer, the mixed number and the decimal value.

Fraction rules

  • Add: a/b + c/d = (a×d + c×b) / (b×d)
  • Subtract: a/b − c/d = (a×d − c×b) / (b×d)
  • Multiply: a/b × c/d = (a×c) / (b×d)
  • Divide: a/b ÷ c/d = (a×d) / (b×c)

Example: 1/2 + 3/4 = (1×4 + 3×2) / (2×4) = 10/8. Dividing the top and bottom by their greatest common divisor, 2, gives 5/4, or 1 1/4 as a mixed number.

Simplifying fractions

To reduce a fraction to lowest terms, divide the numerator and denominator by their greatest common divisor (GCD). 18/24 has a GCD of 6, so it simplifies to 3/4.

Mixed numbers

To enter a mixed number such as 2 1/3, convert it to an improper fraction first: 2 × 3 + 1 = 7, so it is 7/3.

Frequently asked questions

How do I add fractions with different denominators?

Convert them to a common denominator, add the numerators and simplify. For example, 1/3 + 1/4 = 4/12 + 3/12 = 7/12.

How do I divide fractions?

Multiply the first fraction by the reciprocal of the second: a/b ÷ c/d = a/b × d/c.

How do I simplify a fraction?

Divide the numerator and denominator by their greatest common divisor.

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