Fraction Calculator
Add, subtract, multiply and divide fractions and mixed numbers, with simplified answers and the working shown.
Add, subtract, multiply or divide fractions
Leave the whole-number box empty for a simple fraction, or fill it in for a mixed number.
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Simplify a fraction to lowest terms
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Convert a decimal to a fraction
Repeating decimals use brackets: type 0.(3) for 0.333… or 0.1(6) for 0.1666…
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How it works
Three fraction calculators on one page, all updating as you type. The first one adds, subtracts, multiplies or divides two fractions or mixed numbers. Addition and subtraction put both fractions over a common denominator (the product of the two denominators) before combining the numerators; multiplication multiplies numerators and denominators straight across; division multiplies by the reciprocal of the second fraction. Every answer is then reduced to lowest terms by dividing the numerator and denominator by their greatest common divisor, and shown as a mixed number, a decimal and a percentage. The working is printed underneath so you can check each step by hand.
The second calculator simplifies any fraction, and the third turns a decimal into an exact
fraction — including repeating decimals, which you write with brackets like
0.(3) for one third. All of the arithmetic runs in JavaScript inside your
browser: nothing is uploaded, there is no sign-up and there are no ads. Copy any single
answer, copy them all, or download the lot as a plain text file.
Frequently asked questions
How do you add fractions with different denominators?
Put both fractions over a common denominator, then add the numerators. For 1/2 + 1/3 the common denominator is 6, so 1/2 becomes 3/6 and 1/3 becomes 2/6, giving 5/6. The calculator does this automatically and prints the common-denominator step underneath the answer, then reduces the result to lowest terms.
Can it handle mixed numbers like 2 1/2?
Yes. Each fraction has a whole-number box next to its numerator and denominator, so 2 1/2 is entered as 2, 1 and 2. The tool converts mixed numbers to improper fractions before calculating (2 1/2 becomes 5/2) and shows the answer as an improper fraction, a mixed number, a decimal and a percentage.
How do I turn a repeating decimal into a fraction?
Type the repeating digits in brackets: 0.(3) for 0.333… gives 1/3, and 0.1(6) for 0.1666… gives 1/6. Terminating decimals work as normal, so 0.375 becomes 3/8. Every answer is reduced by dividing the numerator and denominator by their greatest common divisor.