How to use it
- Type the first value (Fraction A) as a whole number (
3), a fraction (5/2) or a mixed number (2 1/2). - Pick an operation from the middle drop-down: add (+), subtract (−), multiply (×) or divide (÷).
- Type the second value (Fraction B) the same way. The result appears instantly below, no button to press, along with a step-by-step breakdown of how it was calculated.
You can type negative numbers in either box, and improper fractions like 7/2 are perfectly fine. Leave a box blank and it is treated as 0. Every answer is automatically reduced to its lowest terms.
The fraction formulas
Behind the scenes the tool uses the classic rules. Addition:a/b + c/d = (a·d + c·b) / (b·d). Subtraction is the same with a minus sign. Multiplication: a/b × c/d = (a·c) / (b·d). Division:a/b ÷ c/d = (a·d) / (b·c), that is, multiply by the reciprocal of the second fraction. After computing the raw result it divides the numerator and denominator by their greatest common divisor (GCD) so the fraction is always shown in simplest form.
Fraction, mixed number and decimal
The same answer is shown three ways so you can use whichever you need. The simplified fraction is the reduced form, for example 5/6. The mixed number splits an improper fraction into a whole part and a proper fraction, so 7/3 becomes 2 1/3. The decimal is the numerator divided by the denominator, rounded for readability, handy when you need to plug the value into another calculation.
Handling zero and errors
A fraction is undefined when its denominator is 0, so the calculator shows a clear error if either denominator is left at zero. Division is also undefined when the second fraction equals zero (a zero numerator over any denominator), and that case is caught too. Fix the highlighted input and the result reappears immediately.
Frequently asked questions
Can it work with negative fractions?
Yes. Put a minus sign in front of either value, for example -5/2 or -2 1/2. The result keeps the correct overall sign and is shown with the negative on the whole value.
What is an improper fraction?
An improper fraction has a numerator larger than its denominator, like 7/3. The calculator accepts these and also shows the equivalent mixed number, e.g. 2 1/3.
Why does it show a dash and an error?
That happens when a denominator is 0 (a fraction can't have a zero denominator) or when you divide by a fraction that equals zero. Correct the input and the answer returns.
How do I add or subtract two fractions?
Give both fractions a common denominator by cross-multiplying, add or subtract the numerators, then reduce. For example, 1/2 + 1/3 = 3/6 + 2/6 = 5/6. The calculator shows every one of these steps as you type.
How are fractions multiplied and divided?
To multiply, multiply the numerators together and the denominators together. To divide, flip the second fraction and multiply. The result is always shown reduced to lowest terms.
Can I type a mixed number like 2 1/2?
Yes. Enter a whole number (3), a plain fraction (5/2) or a mixed number (2 1/2) in either box, and the result is shown the same three ways plus a mixed number whenever the answer is 1 or greater.
Is the fraction calculator private?
Yes. Every calculation runs with JavaScript. Nothing you type is ever sent to a server or stored anywhere.
Decimal results are rounded for display; for exact work use the fraction form.