Tools/Math Tools/Fraction Calculator

Fraction Calculator Free - Add, Subtract, Simplify

Free fraction calculator to add, subtract, multiply, divide, and simplify fractions with decimal, mixed number, and percentage output.

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About this tool

Fraction arithmetic requires finding a common denominator, multiplying numerators, and reducing the result - steps that are easy to get wrong by hand. This fraction calculator online free handles all four operations - addition, subtraction, multiplication, and division - and automatically reduces the result to its lowest terms using the greatest common factor, then converts that same answer into a decimal, a mixed number, and a percentage.

This fraction calculator adds, subtracts, multiplies, or divides two fractions and returns the result as a simplified fraction, a decimal, a mixed number, and a percentage - all four formats calculated from the same operation at once.

How to Use Fraction Calculator

Enter Fractions

Add the first fraction, choose an operation, and enter the second fraction.

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Calculate

The tool performs the selected fraction operation instantly.

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Simplify Result

Review the simplified fraction and decimal form.

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Use Alternate Formats

Check mixed number and percentage output when needed.

Common Workflows

Add or Subtract Two Fractions

Enter both fractions as numerator/denominator, choose Add or Subtract, and read the simplified result alongside its decimal, mixed number, and percentage.

Multiply or Divide Two Fractions

Switch the Operation dropdown to Multiply or Divide - the same four output formats update instantly.

Convert a Fraction to a Decimal or Percentage

Enter the fraction as Fraction A, set Fraction B to 1/1 with Multiply selected, and read the Decimal and Percentage outputs directly.

Work with Improper Fractions

Type improper fractions like 7/4 or 11/3 directly into either field - the Mixed Number output converts the result to a whole-number-plus-fraction form automatically.

Simplify a Single Fraction

Enter the fraction in Fraction A, set Fraction B to 1/1 with Multiply selected, and read the Simplified Fraction output.

Best For

Performs all four fraction operations - addition, subtraction, multiplication, and division - and returns the simplified fraction, decimal, mixed number, and percentage together.
Automatically reduces every result to its lowest terms using the greatest common factor, so there's no separate simplification step.
Accepts proper and improper fractions typed as numerator/denominator (like 7/4) - mixed-number input like "2 3/4" isn't supported, only mixed-number output.

Examples

Add two fractions with different denominators

Input

Fraction A 1/2, Operation Add, Fraction B 3/4

Result

Simplified Fraction 5/4, Decimal 1.2500, Mixed Number 1 1/4, Percentage 125.00%

The calculator finds a common denominator, adds the numerators, then reduces the result using the greatest common factor before converting it to the other three formats.

Use Cases

Checking fraction homework

Enter the same two fractions and operation from a worksheet problem to verify a hand-worked answer, including the simplified form.

Adjusting a recipe measurement

Add or multiply fractional cup or teaspoon amounts to scale a recipe up or down.

Converting a fraction to a decimal for a calculation

Enter the fraction and read the Decimal output directly instead of dividing by hand.

Common Mistakes

Problem

Typing a mixed number like "2 3/4"

Solution

The input fields only accept numerator/denominator format (like 11/4) - a mixed number with a space isn't recognized and shows "Invalid fraction".

Problem

Entering a whole number without a slash

Solution

A plain number like "5" isn't accepted either - enter it as a fraction instead, such as 5/1.

Problem

Expecting a negative Mixed Number to show a minus sign

Solution

For a negative result, the Simplified Fraction, Decimal, and Percentage outputs correctly show the negative sign, but the Mixed Number output can display without it - check the other three fields to confirm the sign.

Problem

Entering 0 as a denominator

Solution

A zero denominator (like 3/0) isn't a valid fraction and shows "Invalid fraction" rather than a specific error message.

Tips & Best Practices

Use numerator/denominator format for every input

Both fields expect a plain fraction like 3/4 or 11/4 - convert any mixed number to an improper fraction before entering it.

Read all four outputs together

The Simplified Fraction, Decimal, Mixed Number, and Percentage are the same answer in different formats - use whichever one matches what you need.

Double-check the sign on negative results using Decimal or Percentage

If a subtraction produces a negative result, confirm the sign using the Decimal or Percentage field rather than Mixed Number.

Enter improper fractions directly rather than converting them first

There's no need to simplify a fraction before entering it - 14/8 and 7/4 produce the same simplified result.

Limitations

No mixed-number input

Only numerator/denominator input is accepted (like 7/4) - typing a mixed number such as "2 3/4" isn't recognized. Convert to an improper fraction first.

No plain whole-number input

A bare number like "5" isn't recognized as a fraction - enter it with a denominator, such as 5/1.

No step-by-step working shown

The tool returns the final simplified fraction, decimal, mixed number, and percentage - it doesn't display the intermediate common-denominator or multiplication steps.

Negative Mixed Number output can drop the minus sign

For a negative result, the Mixed Number field can display without its negative sign (for example, showing "0 1/2" instead of "-1/2"), even though the Simplified Fraction, Decimal, and Percentage fields correctly show the negative value.

Only two fractions per calculation

The tool operates on exactly two fractions at a time - there's no built-in way to chain three or more fractions in one calculation.

Comparisons

Simplified Fraction vs Decimal vs Percentage: The Same Answer in Three Formats

All three outputs come from the same calculated result - the choice is about which format fits your task.

	Simplified Fraction / Mixed Number	Decimal / Percentage
What it shows	The exact answer in lowest terms, or as a whole number plus a fraction	The same answer rounded to a fixed number of decimal places, or as a percentage
Best for	Homework, recipes, and measurements expressed in fractions	Digital calculations, comparisons, and contexts that expect a decimal or percent
Same underlying value?	Yes - both come from the same reduced numerator and denominator	Yes - both are the same value converted to a different format

Which should you use?

Use the Simplified Fraction or Mixed Number for a fraction-based answer, and Decimal or Percentage when the next step in your work expects a plain number.

FAQs

Most visitors want a result in whatever format matches how the question was asked - a fraction for homework, a decimal for a calculation, or a percentage for a comparison - which is why every result is shown in all four formats at once. The FAQs below also cover exactly which input formats are supported.