Fraction Calculator
Add, subtract, multiply or divide two fractions and reduce the answer.
Your result
MATHEnter your values and select calculate.
On this page How it works & practical examples
How to use the Fraction Calculator
Enter integers for the numerator and denominator of each fraction. Addition and subtraction use a common denominator, while multiplication multiplies numerators and denominators directly. Division reverses the second fraction and multiplies. The result is reduced using the greatest common divisor, and its sign is normalized so that the denominator is positive.
The calculation
Worked example
Adding 1/2 and 1/3 gives 5/6, or approximately 0.8333333333. Multiplying them gives 1/6.
Assumptions and limits
A denominator cannot be zero. Division by a zero fraction is also undefined, even when its denominator is valid. Inputs are limited to one million in magnitude to keep intermediate whole-number arithmetic within JavaScript’s exact-integer range. The reduced fraction is exact within these limits, whereas its decimal equivalent is rounded.
Common questions
How do I enter a mixed number?
Convert it to an improper fraction first. For example, 2 1/3 becomes 7/3.
Can I use a negative denominator?
Yes. The output moves the negative sign to the numerator so equivalent fractions have a consistent form.