Fraction Calculator

Add, subtract, multiply or divide two fractions and get the result in lowest terms, as a mixed number and as a decimal.

Reviewed by the WorldCalcs team · Methodology · Last reviewed: June 2026

Result

5/6

Mixed number: 5/6

Decimal: 0.833333

What is a fraction?

A fraction represents part of a whole, written as a numerator over a denominator — for example, 3/4 means three parts out of four. The denominator is how many equal parts the whole is divided into, and the numerator is how many of those parts you have. A fraction calculator lets you combine two fractions using the four basic operations and shows the answer in its simplest form.

How fractions are calculated

To add or subtract, give both fractions a common denominator, combine the numerators, then simplify: a/b + c/d = (a·d + c·b) / (b·d). To multiply, multiply the numerators and the denominators: a/b × c/d = (a·c)/(b·d). To divide, multiply the first fraction by the reciprocal of the second: a/b ÷ c/d = (a·d)/(b·c). Every result is reduced to lowest terms by dividing the numerator and denominator by their greatest common divisor.

Example

1/2 + 1/3: the common denominator is 6, so 1/2 = 3/6 and 1/3 = 2/6. Adding gives 5/6, which is already in lowest terms and equals about 0.833. As another example, 7/8 + 2/8 = 9/8, which simplifies to the mixed number 1 1/8, or 1.125 as a decimal.

All calculations happen in your browser. Nothing is sent, stored, or tracked.

Results are estimates and may contain errors — for general information only, not professional advice. Always verify before relying on them. Disclaimer

How to use

Enter the numerator and denominator of each fraction, pick an operation, and read the result.

The answer is shown three ways: simplified fraction, mixed number, and decimal. Denominators of zero are flagged instead of producing a result.

Frequently asked questions

How do you add fractions with different denominators?+

Find a common denominator (multiplying the two denominators always works), rewrite each fraction with it, add the numerators, then simplify to lowest terms.

What is a mixed number?+

A mixed number combines a whole number and a proper fraction, such as 1 1/8. It is another way of writing an improper fraction like 9/8, where the numerator is larger than the denominator.

How do you simplify a fraction?+

Divide both the numerator and denominator by their greatest common divisor. For example, 4/8 becomes 1/2 because both divide by 4.

How do you divide two fractions?+

Keep the first fraction, change divide to multiply, and flip the second fraction (its reciprocal). So 1/2 ÷ 3/4 = 1/2 × 4/3 = 4/6 = 2/3.

Can a fraction be negative?+

Yes. If either the numerator or denominator is negative, the fraction is negative. This calculator keeps the sign on the numerator and simplifies as usual.

What is the decimal value of a fraction?+

Divide the numerator by the denominator. For example, 5/6 = 5 ÷ 6 = 0.8333…, a repeating decimal.