Fraction Calculator
Add, subtract, multiply and divide fractions, with simplified results.
All calculations happen locally in your browser — nothing is uploaded, stored or tracked.
Enter the two fractions
Numerators and denominators in the four boxes.
Pick the operation
Add, subtract, multiply or divide.
Read the result
Simplified fraction, mixed number and decimal.
What Is a Fraction Calculator?
A fraction calculator performs arithmetic on fractions — numbers written as a numerator over a denominator — and presents the answer in the clearest form: simplified, as a mixed number when the result is greater than one, and as a decimal.
The rules are the ones taught in school: common denominators for addition and subtraction, multiplication straight across, and "flip and multiply" for division. The calculator does the simplification using the greatest common divisor, so results are always in lowest terms.
The Rules
After each operation the result is reduced by dividing numerator and denominator by their greatest common divisor. Improper fractions (where the numerator is larger) are also shown as mixed numbers.
Your data never leaves your device.
Every calculation on this site runs in your browser using vanilla JavaScript. Nothing is uploaded, stored or tracked.
- 100% local, client-side calculations
- No data stored on any server
- No tracking, no analytics, no ads scripts
- Works offline once loaded
Frequently Asked Questions
How do you add fractions with different denominators?
Find a common denominator (multiply the two denominators), convert both fractions, then add the numerators. The calculator does this automatically.
How do you divide fractions?
Multiply the first fraction by the reciprocal of the second: a/b ÷ c/d = (a × d) / (b × c).
What is 1/2 + 1/3?
5/6. Using a common denominator of 6: 3/6 + 2/6 = 5/6.
What is an improper fraction?
A fraction whose numerator is larger than its denominator, like 7/4. It can be written as the mixed number 1 3/4.
Can I simplify a single fraction?
Yes — choose the "simplify" mode and enter just one fraction; it will be reduced to lowest terms and shown as a decimal.