How Fraction Calculator Works
Addition and subtraction find a common denominator by cross-multiplying, then combine the numerators. Multiplication multiplies numerators and denominators directly, and division multiplies by the reciprocal of the second fraction. The result is then reduced by dividing both numerator and denominator by their greatest common divisor, and converted to a mixed number if it's an improper fraction.
How to Use This Tool
- Enter your first fraction, such as 3/4 (a whole number like 5 also works).
- Choose the operation: add, subtract, multiply or divide.
- Enter your second fraction.
- Select Calculate to see the reduced result, with a mixed-number form if applicable.
Example
3/4 + 5/6 = 38/24, which reduces to 19/12, or as a mixed number, 1 7/12.
Helpful Tips
- A whole number like 5 is treated the same as the fraction 5/1, so you can mix whole numbers and fractions freely.
- Negative fractions are supported — put the minus sign on the numerator, like -3/4.
- The result is always shown fully reduced, so you never need to simplify it yourself afterward.
Frequently Asked Questions
What format should I use to enter a fraction?
Type it as numerator/denominator, such as 3/4. A plain whole number like 5 is also accepted and treated as 5/1.
Why do I get a divide-by-zero error?
This happens if the denominator of a fraction you entered is 0, or if you try to divide by a fraction whose value is 0 — both are mathematically undefined.
Does the answer show as a mixed number or an improper fraction?
Both — the result box shows the reduced improper fraction, and a mixed-number form (like 1 7/12) whenever the fraction is greater than one.
Can I use negative fractions?
Yes, put a minus sign on the numerator or the whole fraction, such as -3/4 or -5.
This tool runs entirely in your browser. Your input is not uploaded to any server.