The formula
How it works
Add, subtract, multiply or divide two fractions and get the answer reduced to its simplest form — plus the decimal value and, where it applies, a mixed number. No more hunting for common denominators by hand.
FAQ
How do I add fractions with different denominators?
Give them a common denominator first by cross-multiplying: a/b + c/d becomes (ad + bc) / bd. Then reduce. The calculator does all of this and shows the simplified result.
What is a mixed number?
A mixed number combines a whole number and a proper fraction, like 1½. When a result is bigger than one, the calculator also shows it in this form as well as an improper fraction.
How do I multiply or divide fractions?
To multiply, multiply the numerators together and the denominators together: a/b × c/d = ac/bd. To divide, flip the second fraction and multiply instead: a/b ÷ c/d = ad/bc.
Can I use negative numbers in the fractions?
Yes, enter a negative numerator (or denominator) and the calculator handles the sign correctly, showing the result as a properly signed simplified fraction.
What does it mean to simplify or reduce a fraction?
Simplifying means dividing the numerator and denominator by their greatest common factor so the fraction is expressed in its smallest equivalent terms, like turning 4/8 into 1/2.
Can I enter whole numbers instead of fractions?
Yes, just set the denominator to 1 — for example, entering 5 as the numerator and 1 as the denominator treats it as the whole number 5 in the calculation.
Why is my answer shown as a negative fraction?
A result is negative when exactly one of the two fractions involved is negative. The calculator keeps the negative sign on the numerator and puts the fraction in standard form.
About the fraction calculator
This calculator adds, subtracts, multiplies and divides two fractions, then reduces the answer to its lowest terms. Fractions trip a lot of people up because each operation has its own rule and the result usually needs simplifying afterwards. By handling the common denominators and the reducing automatically, this tool gives a clean, correct answer along with the decimal it represents.
How to use it
Enter the top and bottom of each fraction, and choose whether to add, subtract, multiply or divide. The calculator shows the result as a simplified fraction, as a decimal, and — if it is larger than one — as a mixed number. For example, 1/2 + 1/3 gives 5/6, or about 0.833. Negative numerators are allowed, so you can work with negative fractions too.
The formula
Adding uses a common denominator: , and subtracting is the same with a minus. Multiplying is straightforward, , and dividing flips the second fraction, . Whatever the operation, the result is then reduced by dividing the top and bottom by their greatest common factor.
Where it is used
Fractions are everywhere outside the classroom: halving or scaling a recipe, splitting a bill, measuring in inches, reading tools and timber sizes, and working with ratios and probabilities. Being able to combine them reliably — and simplify the result — is a core arithmetic skill, and this calculator saves time and avoids the small slips that make fraction work error-prone.