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Fraction Calculator

Free fraction calculator for adding, subtracting, multiplying and dividing fractions. Results auto-simplify and show as fraction, decimal and mixed number.

About this tool

Fractions trip up even confident math students, especially when denominators differ. Our free fraction calculator adds, subtracts, multiplies, and divides fractions, then simplifies the answer automatically.

Every result is shown three ways: as a reduced fraction, as a decimal, and as a mixed number. Perfect for homework checks and recipe scaling.

How to use

Enter the top number (numerator) and bottom number (denominator) of the first fraction, pick the operation, then enter the second fraction the same way. Denominators cannot be zero.

Press Calculate to see the simplified fraction, its decimal value, and the mixed-number form. Negative results are handled correctly too.

The math behind it

To add or subtract, the calculator finds a common denominator by cross-multiplying: a/b + c/d = (ad + bc) / bd. Multiplication is simpler: multiply tops and bottoms straight across. Division flips the second fraction and multiplies.

The result is reduced by dividing top and bottom by their greatest common divisor (GCD). So 2/4 automatically becomes 1/2, and 7/3 displays as the mixed number 2 1/3.

Frequently asked questions

How do you add fractions with different denominators?
Find a common denominator, convert both fractions, then add the numerators. For 1/2 + 1/3, the common denominator is 6: that becomes 3/6 + 2/6 = 5/6. The calculator does this by cross-multiplying, which always works: a/b + c/d = (ad + bc) / bd. Then it simplifies the result, so you get 5/6 directly without extra steps.
What is a mixed number?
A mixed number combines a whole number with a fraction, like 2 1/3 instead of 7/3. It is often easier to picture - 2 1/3 pizzas is clearer than 7/3 pizzas. The calculator shows this form automatically whenever the result is an improper fraction (numerator larger than denominator). The value is identical, just written differently.
Why does the calculator round my inputs to whole numbers?
By definition, fraction numerators and denominators are integers. If you type a decimal, the tool rounds to the nearest whole number so the fraction math stays valid. If you need to work with decimals directly, use the regular math calculator instead - it handles decimal arithmetic without any rounding.

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