Fraction Calculator
Add, subtract, multiply and divide fractions exactly, reduced and as a mixed number.
Runs entirely in your browser. Nothing is uploaded, logged or stored.
Result, reduced
1/2
- As a mixed number
- already a proper fraction
- As a decimal
- 0.5
Fractions stay fractions here. A third plus a third plus a third is one — which is true, and which a decimal calculator cannot tell you, because 0.333333 three times is not.
How it works
Every step keeps whole numerators and denominators, so nothing is rounded along the way. Addition and subtraction cross-multiply onto a common denominator, division multiplies by the reciprocal, and the answer is reduced at the end by its greatest common divisor — so 6/8 comes back as 3/4 rather than as itself.
The sign always sits on the numerator. −3/4 and 3/−4 are the same number, and writing it one way makes two results comparable.
Examples
| Case | Input | Result |
|---|---|---|
| Different denominators | 1/3 + 1/6 | 1/2 |
| A mixed number | 1 1/2 × 2/3 | 1 |
| Reduced automatically | 2/8 + 2/8 | 1/2, not 4/8 |
Frequently asked questions
How do I type a mixed number?
With a space: 1 1/2 is one and a half. A negative mixed number carries its sign on the whole part, so −1 1/2 is minus one and a half rather than minus one plus a half.
Why does it refuse very large fractions?
Because cross-multiplying two big fractions overflows a machine integer, and past that point the answer silently stops being exact — which is the one thing this page exists to avoid. It refuses rather than return something that looks right.
Is the result always reduced?
Yes. There is only one way to write a fraction in lowest terms, so that is what comes back, along with the mixed form and the decimal for comparison.
Good to know
- The decimal is shown for convenience and is the only part of the answer that may be rounded. A third is 0.3333333333 there and exactly 1/3 above it.