How do I add fractions?

Create a common denominator, add the expanded numerators, and simplify the result.

How do I subtract fractions?

Create a common denominator, then subtract the second expanded numerator from the first.

How do I divide fractions?

Invert the second fraction and multiply it by the first. You cannot divide by a fraction whose value is zero.

How do I simplify a fraction?

Divide the numerator and denominator by their greatest common divisor. For example, 12/18 divided by 6 becomes 2/3.

How do I convert an improper fraction to a mixed number?

Divide the numerator by the denominator. The quotient is the whole number, and the remainder becomes the numerator of the fractional part.

How do I convert a fraction to percent?

Divide the numerator by the denominator and multiply the decimal result by 100. For example, 1/4 = 0.25 = 25%.

Why can a denominator not be zero?

A fraction represents division by the denominator. Division by zero is mathematically undefined.

Tools/🧮 Calculators/Fraction Calculator

Fraction Calculator

Add, subtract, multiply, divide, and simplify fractions or convert them to decimal, percent, and mixed numbers.

Version 1.0 · Last Updated: August 10, 2026 · Maintained by ToolLarder

Fraction operations and conversions

The Fraction Calculator performs the four basic operations with automatic simplification. Conversion mode displays a single fraction as a mixed number, decimal, and percentage at the same time.

Adding and subtracting fractions

Create a common denominator, add or subtract the expanded numerators, and simplify the result.

a/b ± c/d = (a×d ± c×b) / (b×d)

Multiplying fractions

Multiply the numerators together and the denominators together, then reduce the fraction using the GCD.

a/b × c/d = (a×c) / (b×d)

Dividing fractions

Invert the second fraction and multiply. The numerator of the second fraction cannot be zero.

a/b ÷ c/d = (a×d) / (b×c)

Simplifying fractions

Divide the numerator and denominator by their greatest common divisor to find the equivalent fraction in lowest terms.

a/b → (a÷GCD) / (b÷GCD)

Improper fraction to mixed number

Divide the numerator by the denominator. The quotient is the whole part and the remainder becomes the new numerator.

7/3 = 2 1/3

Fraction to decimal and percent

Divide the numerator by the denominator for the decimal and multiply that result by 100 for the percentage.

a ÷ b = decimal → decimal × 100 = percent

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