Fraction Calculator

How the calculator works

Each fraction is converted to an improper fraction (a mixed number such as 1 1/2 becomes 3/2) and the operation is carried out with exact integer arithmetic. The result is then simplified by dividing the numerator and denominator by their greatest common divisor.

• Add / subtract: a/b + c/d = (ad + bc) / bd
• Multiply: a/b × c/d = ac / bd
• Divide: a/b ÷ c/d = ad / bc (you cannot divide by 0)

Examples

• 1/2 + 1/3 = 5/6 ≈ 0.8333…
• 3/4 − 1/6 = 7/12
• 2/3 × 3/8 = 1/4 = 0.25
• 1 1/2 ÷ 3/4 = 2
• 1/7 = 0.(142857) as a decimal: the digits in parentheses repeat

Notes

• Use the sign selector (+ or −) to make a fraction negative; the numerator, denominator and whole part are whole numbers of 0 or more.
• The denominator must be 1 or more.
• Decimals are checked for a repeating part up to 1,000 decimal places. If the repetition cannot be determined within that limit, only the first digits are shown and the page says so.

Frequently asked questions

How do I add fractions with different denominators?

Rewrite both fractions with a common denominator, add the numerators, then simplify. This calculator does it for you: 1/2 + 1/3 = 3/6 + 2/6 = 5/6.

How do I enter a mixed number?

Enter the whole part in the "Whole" box, and the numerator and denominator of the fractional part in the other boxes. For 2 1/3, enter 2, 1 and 3.

How do I turn a fraction into a decimal?

The decimal is shown under the answer. When the decimal repeats, the repeating digits appear in parentheses, for example 1/3 = 0.(3).