Fraction calculator
Enter the numerator and denominator of each fraction and pick an operation. The arithmetic is exact, with no rounding.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter numerator 1, denominator 1, operation, numerator 2 and denominator 2.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
a/b + c/d = (ad + bc)/bd, a/b - c/d = (ad - bc)/bd, a/b × c/d = ac/bd, a/b ÷ c/d = ad/bc, then simplify
Example
Inputs: Numerator 1 = 1, Denominator 1 = 2, Operation = Add +, Numerator 2 = 1, Denominator 2 = 3. Result: Result in lowest terms: 5/6; Decimal: 0.8333333333.
Limits and caveats
- Numerators and denominators must be whole numbers. Convert mixed numbers such as 2 1/3 to improper fractions first.
Questions about this tool
How do I add 1/2 and 1/3?
Use a common denominator of 6: 3/6 + 2/6 = 5/6.
How do I divide one fraction by another?
Multiply by the reciprocal of the second. For example, 3/4 ÷ 3/8 = 3/4 × 8/3 = 2.
Where do I put a minus sign?
In either the numerator or the denominator; the result always shows the sign on the numerator.