Fraction Calculator
Add, subtract, multiply or divide two fractions. Automatic simplification with decimal and mixed-number outputs.
About Fraction Calculator
The Fraction Calculator adds, subtracts, multiplies and divides two fractions and returns the simplified result, its decimal value and a mixed-number form where applicable. Simplification uses the greatest common divisor, so answers are always in lowest terms.
For addition and subtraction, the calculator builds a common denominator before combining the numerators. Multiplication works across numerators and denominators, while division multiplies by the reciprocal of the second fraction. Seeing the reduced, decimal and mixed forms together helps connect the different representations.
It handles negative fractions and warns clearly when a denominator is zero. Inputs remain exact fractions during the operation, avoiding the early rounding that can happen when fractions are first converted to decimals.
Keeping the exact rational form matters whenever a decimal would hide a repeating pattern — for example, 1/3 × 3 stays exactly 1 instead of drifting through 0.333… approximations. That makes the tool especially reliable for homework checks and measurement math where the textbook answer is expected as a reduced fraction.
Improper results are shown both as a single fraction and as a mixed number so you can match whichever form a worksheet or recipe uses. Sign placement follows the usual convention of attaching the negative to the overall value rather than scattering minuses across numerator and denominator after reduction.
How Fraction Calculator works in practice
- 1Enter the first fraction — numerator on top, denominator below.
- 2Pick an operator: +, −, × or ÷.
- 3Enter the second fraction the same way.
- 4Confirm neither denominator is zero before reading the answer.
- 5Read the simplified result, plus the decimal and mixed-number equivalents below.
Jobs this tool is built for
- Add recipe quantities such as 3/4 cup and 2/3 cup without converting by hand.
- Check fraction exercises and compare the simplified result with your working.
- Divide measurements in woodworking, sewing or other projects that use fractional units.
- Convert an improper fraction result into a mixed number for easier reading.
- Scale a board cut or fabric length expressed in halves and eighths without a tape-measure mental conversion.
- Verify that two different fraction answers from classmates reduce to the same lowest terms.
What you can do here
- All four basic operations
- Automatic simplification via GCD
- Decimal and mixed-number equivalents
- Handles negative fractions and zero numerators
- Exact rational arithmetic before any decimal display
Limits and honest caveats
- Enter mixed numbers as improper fractions first (for example, 2 1/4 becomes 9/4).
- A zero denominator is undefined; the UI will not invent a numeric answer in that case.
- The fraction result is exact; the decimal display may round repeating values for readability.
Common questions about Fraction Calculator
Does it handle mixed numbers as input?
Not directly — convert 1 1/2 to the improper fraction 3/2 first.
What happens if I enter 0 as denominator?
The result shows as "—" because dividing by zero is undefined.
Why does the answer have a different denominator?
Addition and subtraction require a common denominator, and the final fraction is then reduced by dividing both parts by their greatest common divisor.
Are decimal answers rounded?
The fraction is the exact result. Its decimal equivalent may be rounded for display when the value repeats or has more digits than the interface can show.
How do I divide one fraction by another?
Choose the ÷ operator. The calculator multiplies the first fraction by the reciprocal of the second, then simplifies — the same method taught in school.
Can both numerators be zero?
Yes. A zero numerator yields a zero result for addition, subtraction and multiplication as long as denominators are valid. Division by a zero fraction (0/n) is still undefined.
This page was written by the ToolSink team to explain how Fraction Calculator works on this site — it is not syndicated, scraped, or spun from another publisher. How we write tool guides · Site updates · About ToolSink.
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