Fraction Calculator
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Add, subtract, multiply and divide fractions, with the answer in lowest terms.
- Type a fraction like 3/4, a mixed number like 2 3/4, or a whole number
- Pick the operation
- Read the answer as a fraction, a mixed number and a decimal
About this tool
Fractions kept as fractions, from what you type to what comes back. That is the whole reason to use a fraction calculator rather than typing the division into any calculator at all. A third plus a third plus a third worked out in decimals is 0.9999999999999999. Kept as a pair of whole numbers it is exactly 1, every time, because nothing was ever approximated. It takes mixed numbers — type "2 3/4" — and gives them back, since "1 1/2" is what people expect to read and 3/2 is what a computer prefers. The improper form, the mixed form and the decimal all come back together, so whichever one you needed is there. Answers are always reduced. 4/8 is shown as 1/2, not because it is more correct but because it is what anybody would write down, and a calculator that made you simplify its output by hand would have done half the job. Useful for recipes, woodwork, sheet music, imperial measurements and homework. It runs entirely in your browser.
Frequently asked questions
Can I type mixed numbers?
Yes — "2 3/4" with a space works, and so does a plain whole number. Negative mixed numbers are read as a whole, so "-2 1/2" is minus two and a half rather than minus two plus a half. That sign handling is the classic bug in tools that accept mixed numbers.
Why not just use decimals?
Because they do not always come out. A third is 0.333… however many places you keep, so a third plus a third plus a third computed in decimals is 0.9999999999999999. As a pair of whole numbers it is exactly 1, and nothing was rounded on the way.
Does it simplify the answer?
Always. 4/8 comes back as 1/2. A calculator that handed you an unsimplified fraction would have left you the last step, which is the fiddly one — and simplifying is the same greatest-common-divisor step whichever operation you asked for.
What about dividing by a fraction?
It works the way you were taught: dividing by a fraction is multiplying by it upside down. Dividing by zero is refused, including when the zero is written as 0/5, because there is no answer to give.
Can I use it for imperial measurements?
Yes, that is one of the main reasons people reach for one. Sixteenths and thirty-seconds of an inch add up exactly here, and the mixed-number output is the form a tape measure is marked in.
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