How to Calculate Fractions
Fractions appear in cooking, construction, finance, and education. Adding and subtracting fractions requires finding a common denominator, while multiplying and dividing follow simpler rules. This calculator handles all four operations and automatically simplifies the result using the greatest common divisor.
How to Use This Calculator
- Enter the first fraction by typing the numerator (top number) and denominator (bottom number) in the left-hand inputs.
- Choose the operation from the dropdown: addition (+), subtraction (−), multiplication (×), or division (÷).
- Enter the second fraction in the right-hand inputs.
- View the result as a simplified fraction and decimal in the blue result box. Results update instantly as you type.
How It Works
For addition and subtraction, the calculator finds the common denominator by multiplying the two denominators, adjusts each numerator, and performs the operation. For multiplication, it multiplies numerators together and denominators together. For division, it flips the second fraction and multiplies. The result is then simplified by dividing both numerator and denominator by their greatest common divisor (GCD), calculated using the Euclidean algorithm. The decimal equivalent is obtained by dividing the numerator by the denominator. All calculations run locally in your browser.
Frequently Asked Questions
How do I add fractions?
To add fractions, find a common denominator by multiplying the two denominators together, adjust each numerator accordingly, add the numerators, and simplify the result. For example, 1/3 + 1/4 becomes 4/12 + 3/12 = 7/12.
How do I multiply fractions?
Multiplying fractions is straightforward — multiply the numerators together and multiply the denominators together. For example, 2/3 times 3/4 equals 6/12, which simplifies to 1/2.
How do I divide fractions?
To divide fractions, flip the second fraction (take its reciprocal) and multiply. For example, 1/2 divided by 3/4 becomes 1/2 times 4/3, which equals 4/6, simplified to 2/3.
What does it mean to simplify a fraction?
Simplifying a fraction means dividing both the numerator and denominator by their greatest common divisor (GCD). For example, 8/12 simplified is 2/3 because the GCD of 8 and 12 is 4.
What is a mixed number?
A mixed number combines a whole number with a fraction, such as 2 and 3/4. To convert a mixed number to an improper fraction, multiply the whole number by the denominator, add the numerator, and place over the denominator: 2 and 3/4 becomes 11/4.
How do I convert a fraction to a decimal?
Divide the numerator by the denominator. For example, 3/4 as a decimal is 3 divided by 4, which equals 0.75. Some fractions produce repeating decimals, such as 1/3 which equals 0.333 repeating.