Fraction Calculator
Enter two fractions and choose an operation. Leave the whole number blank for a simple fraction, or fill it in for a mixed number.
Result
- As a decimal
- 1.25
- Calculation
- 1/2 + 3/4 = 5/4
- Unsimplified result
- 10/8
- Comparison
- 1/2 < 3/4
- Least common denominator
- 4
Formula
- a/b + c/d = (a × d + c × b) ÷ (b × d)
- a/b − c/d = (a × d − c × b) ÷ (b × d)
- a/b × c/d = (a × c) ÷ (b × d)
- a/b ÷ c/d = (a × d) ÷ (b × c)
- Simplify by dividing top and bottom by their greatest common factor
How the Fraction Calculator works
To add or subtract fractions they need a common denominator. Multiply each numerator by the other denominator, combine, and put the result over the product of the denominators. Then simplify.
Multiplying is simpler: multiply the numerators together and the denominators together. To divide, flip the second fraction and multiply. Mixed numbers are first converted to improper fractions.
Worked example
1/2 + 3/4 = (1 × 4 + 3 × 2) ÷ (2 × 4) = 10/8. Dividing top and bottom by 2 gives 5/4, which is 1 1/4 or 1.25.
Frequently asked questions
How do I add fractions with different denominators?
Rewrite them with a common denominator. For 1/3 + 1/4, use 12: 4/12 + 3/12 = 7/12.
How do I divide fractions?
Multiply by the reciprocal of the second fraction. 2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6.
How do I convert a mixed number to an improper fraction?
Multiply the whole number by the denominator and add the numerator. 2 3/5 is (2 × 5 + 3)/5 = 13/5.
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