Fraction Calculator

Our free fraction calculator helps you solve any fraction problem with detailed step-by-step explanations. Whether you need to add fractions with different denominators, convert mixed numbers, or simplify complex fractions, this calculator shows you exactly how it's done.

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Fractions Calculator calculator

1/2
First Fraction
+
1/3
Second Fraction
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5/6
Result
Visual Comparison
1/2
50%
1/3
33%
5/6
83%
Quick:

lightbulb Tips

  • Results are automatically simplified
  • Visual pie charts show proportions

How to Use the Fractions Calculator

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Choose Operation

Select arithmetic, simplify, convert, or compare fractions.

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Enter Fractions

Input numerators and denominators. Add whole numbers for mixed fractions.

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Calculate

Click calculate to see results with step-by-step explanation.

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View Results

See simplified fraction, decimal, percentage, and detailed steps.

The Formula

To add or subtract fractions, find a common denominator, adjust numerators accordingly, then combine. Multiply by multiplying numerators and denominators. Divide by multiplying by the reciprocal.

a/b ± c/d = (ad ± bc) / bd

lightbulb Variables Explained

  • a, c Numerators of the fractions
  • b, d Denominators of the fractions
  • ± Addition or subtraction operation

tips_and_updates Pro Tips

1

Find the LCD (Least Common Denominator) for adding/subtracting

2

Multiply straight across: (a/b) × (c/d) = ac/bd

3

Divide by flipping the second fraction and multiplying

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Always simplify your final answer by finding the GCD

5

Convert mixed numbers to improper fractions first

6

To convert to decimal, divide numerator by denominator

Calculate fractions with ease using our free online fraction calculator. Add, subtract, multiply, divide fractions, simplify, and convert between fractions, decimals, and percentages with step-by-step solutions.

Adding and Subtracting Fractions

To add or subtract fractions:

  • find the Least Common Denominator (LCD)
  • convert fractions to equivalent fractions with the LCD
  • then add or subtract numerators

Our calculator handles this automatically and shows each step.

Multiplying and Dividing Fractions

Multiply fractions by multiplying numerators together and denominators together.

Divide by flipping the second fraction and multiplying. Remember: Keep, Change, Flip for division.

Simplifying Fractions

Simplify fractions by finding the Greatest Common Divisor (GCD) of numerator and denominator, then dividing both by it.

A fraction is fully simplified when GCD equals 1.

Converting Fractions

Our converter handles all these transformations:

  • Convert fractions to decimals by dividing.
  • Convert decimals to fractions by placing over powers of 10.
  • Learn how to calculate percentages by multiplying a fraction by 100.

Mixed Numbers and Improper Fractions

Mixed numbers combine whole numbers with fractions (2 1/2).

Improper fractions have numerators larger than denominators (5/2).

Convert between them easily with our calculator.

Step-by-Step Solutions

Every calculation shows detailed steps so you can learn the process.

Perfect for students learning fraction arithmetic or anyone who wants to understand the math behind the answer.

What Is a Fraction and How Does It Work?

A fraction represents a part of a whole, written as two numbers separated by a bar: the numerator on top and the denominator on the bottom. The denominator tells you how many equal parts the whole is divided into, while the numerator tells you how many of those parts you are counting.

For example, in 3/4 the whole is split into 4 equal parts and you are taking 3 of them.

According to Encyclopaedia Britannica, fractions extend the natural numbers so that quantities between whole numbers can be expressed exactly. Any fraction with a denominator that is not zero represents a rational number, and equal fractions like 2/4 and 1/2 name the same value.

How to Find the LCD and GCD for Fraction Math

The Greatest Common Divisor (GCD) is the largest number that divides two integers evenly, and the Least Common Denominator (LCD) is the smallest number that both denominators divide into.

To simplify 12/18, find GCD(12, 18) = 6, then divide to get 2/3.

To add 1/4 + 1/6, find the LCD, which equals the least common multiple of 4 and 6: since LCM(4, 6) = 4 × 6 / GCD(4, 6) = 24 / 2 = 12, the LCD is 12.

As Wolfram MathWorld explains, the GCD and LCM are linked by the identity a × b = GCD(a, b) × LCM(a, b), which our calculator uses to keep denominators as small as possible.

How to Compare Two Fractions Correctly

To compare two fractions quickly, cross-multiply — the same step you use to solve a proportion: multiply the numerator of each fraction by the denominator of the other, then compare the products.

For 2/3 versus 3/4, multiply 2 × 4 = 8 and 3 × 3 = 9; because 8 is less than 9, 2/3 is smaller than 3/4. This works because both products share the same effective denominator, a technique Khan Academy teaches for ordering fractions.

You can also convert each fraction to a decimal and compare: 2/3 ≈ 0.667 and 3/4 = 0.75, confirming 3/4 is larger.

Our comparison mode shows the cross-multiplication and the decimal check side by side.

Real-World Uses of Fraction Calculations

Fractions appear constantly in daily life, which makes fast, accurate fraction math genuinely useful.

  • Cooking recipes call for 3/4 cup of flour or half of a 2/3-cup measure, so scaling a recipe up or down requires multiplying fractions.
  • Woodworking and construction rely on inch fractions like 5/8 and 7/16, where adding board thicknesses means finding a common denominator.
  • Finance uses fractions and their decimal equivalents for interest rates and stock quotes, and probability expresses chances as fractions such as 1/6 for rolling a specific number on a die.

Encyclopaedia Britannica notes that fractional notation predates decimals by millennia, and it still gives exact answers where rounding a decimal would introduce error.

Common Mistakes When Calculating Fractions

  • The most frequent fraction error is adding numerators and denominators directly, such as writing 1/2 + 1/3 = 2/5, which is wrong; you must first find the LCD, giving 3/6 + 2/6 = 5/6.
  • Another common slip is forgetting to flip only the second fraction when dividing, since a ÷ b uses the reciprocal of b, not of a.
  • Students also skip simplifying the final answer, leaving 6/12 instead of 1/2, or misconvert mixed numbers by adding instead of using (whole × denominator + numerator).

Khan Academy stresses checking that a final fraction is fully reduced, meaning the GCD of numerator and denominator equals 1.

Our step-by-step output flags each of these stages so mistakes are easy to catch.

Frequently Asked Questions

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