Fraction Calculator
Add, subtract, multiply, or divide two fractions and read the result as a simplified fraction, a decimal, and a mixed number, live as you type.
Everything is calculated in your browser. The numbers you type are never uploaded.
How to calculate with fractions online
Enter the first fraction
Type a numerator and a denominator into the first fraction. Whole numbers, negatives, and decimals all work.
Enter the second fraction
Fill in the numerator and denominator of the second fraction the same way.
Choose an operation
Pick add, subtract, multiply, or divide, and the result updates the instant you change it or either fraction.
Read and copy the result
The answer appears as a reduced fraction, a decimal, and a mixed number, ready to copy as one line.
Why use this tool
Four operations in one
Add, subtract, multiply, and divide two fractions from a single screen, with the result recalculated live as you edit.
Always fully reduced
Every answer is reduced to its lowest terms by dividing through the greatest common divisor, so 2/4 comes back as 1/2.
Three ways at once
See the result as a simplified fraction, a decimal, and a mixed number side by side, and copy all three together.
Negatives and decimals accepted
Numerators and denominators take negative numbers and decimal points, and the sign of the answer is always shown.
No undefined answers
A zero denominator, or dividing by a fraction that equals zero, is flagged with a clear message instead of a broken result.
Runs entirely in your browser
Everything happens on your device. The numbers you type are never uploaded, stored, or logged.
About this tool
This fraction calculator takes two fractions and one operation and shows the answer three ways at once: as a fraction reduced to its lowest terms, as a decimal, and as a mixed number. Enter a numerator and a denominator for each fraction, choose add, subtract, multiply, or divide, and every field recalculates as you type. Adding 1/2 and 1/3 gives 5/6, which is also 0.8333 and, because it is a proper fraction, stays 5/6 as a mixed number.
Reducing is automatic. The result is divided through by the greatest common divisor of its numerator and denominator, so 6/8 collapses to 3/4 and 10/5 becomes the whole number 2. Improper results are also written as mixed numbers, so 7/3 reads as 2 1/3. Numerators and denominators can be negative or contain a decimal point, and the sign of the answer always sits with the numerator. A denominator of zero, or dividing by a fraction that equals zero, is reported as undefined rather than shown as a wrong number.
Every calculation happens in your browser, so the numbers you enter are never uploaded or stored. To turn a fraction into a percentage, use the percentage calculator, and to reduce a width and height ratio the same way this tool reduces fractions, try the aspect ratio calculator.
Frequently asked questions
- How do I add or subtract fractions?
- Give the two fractions a common denominator, combine the numerators, then reduce. This calculator does it for you: enter both fractions, pick add or subtract, and it returns the answer in lowest terms, for example 1/2 + 1/3 = 5/6.
- How are fractions multiplied and divided?
- To multiply, multiply the numerators together and the denominators together. To divide, flip the second fraction and multiply. Choosing multiply or divide applies the right rule automatically and reduces the result.
- Does it simplify the result?
- Yes. Every answer is reduced to its lowest terms using the greatest common divisor, so 6/8 shows as 3/4 and 4/2 shows as 2. Improper results are also written as a mixed number, such as 2 1/3.
- What happens if a denominator is zero?
- A fraction with a denominator of zero is undefined, and dividing by a fraction that equals zero is also undefined. In both cases the calculator shows a short message instead of a result.
- Can I use negative numbers or decimals?
- Yes. Numerators and denominators accept a leading minus sign and a decimal point, and the answer keeps its sign. A decimal input such as 2.5/4 is handled as an exact fraction.
- Is my data uploaded anywhere?
- No. Everything runs in your browser; nothing is sent to a server.
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