Fraction Calculator

Fraction Calculator

Add, subtract, multiply, and divide fractions with automatic simplification. Results shown in standard, decimal, and mixed number formats.

Last updated: May 2026 | By Patchworkr Team

Perform Fraction Operations
Results appear here...

Fraction Arithmetic Examples

OperationExpressionResult
Add1/2 + 1/35/6
Subtract3/4 − 1/21/4
Multiply2/3 × 3/41/2
Divide3/4 ÷ 1/23/2
Simplify6/83/4

Understanding Fraction Operations

Fractions represent parts of a whole, expressed as a ratio of numerator (top) to denominator (bottom). Fraction arithmetic combines these ratios through well-defined rules that have been fundamental to mathematics for over 4,000 years. When adding or subtracting fractions, you must first find a common denominator—this represents the smallest unit that both fractions can be expressed in. Multiplication is more direct: multiply the numerators together and the denominators together, then simplify. Division of fractions follows the elegant rule: multiply by the reciprocal (flip the second fraction). All fractional results should be simplified to lowest terms by dividing both numerator and denominator by their greatest common divisor (GCD). This calculator performs all these operations automatically, showing results in three useful formats: simplified proper or improper fractions, and decimal equivalents for practical applications like cooking measurements or financial calculations.

Fractions are essential across numerous fields: in engineering for tolerances and measurements, in medicine for dosage calculations, in cooking for recipe scaling, in music for time signatures and note durations, and in construction for blueprint dimensions. Understanding fraction operations builds foundation for advanced mathematics including algebra, calculus, and statistics. The ability to simplify fractions, find common denominators, and recognize equivalent fractions develops mathematical reasoning that extends far beyond fraction arithmetic itself. Many real-world problems naturally involve fractions—splitting costs, combining recipes, calculating probabilities—making this skill practically valuable throughout life. This calculator bridges manual calculation and modern computation, helping you verify your work and understand the underlying mathematical processes.

How to Add, Subtract, Multiply & Divide Fractions

1

Select the operation

Choose whether you want to add, subtract, multiply, or divide fractions from the dropdown menu. This determines which rule applies.

2

Enter the first fraction

Input the numerator (top number) and denominator (bottom number) of the first fraction. The denominator cannot be zero.

3

Enter the second fraction

Input the numerator and denominator of the second fraction. For division, this becomes the divisor (the fraction you're dividing by).

4

Click Calculate

Press the Calculate button to compute the result. The calculator automatically applies the correct arithmetic rules and simplifies the answer.

5

Review results in multiple formats

The result appears as a simplified fraction, decimal equivalent, and mixed number (if applicable), helping you interpret the answer in the most useful form.

Example: Adding 3/4 + 1/2

Adding fractions with different denominators

Problem:
Add 3/4 + 1/2
Step 1:
Find common denominator: LCM(4,2)=4
Step 2:
Convert: 1/2 → 2/4
Step 3:
Add numerators: (3+2)/4 = 5/4
Result:
5/4 or 1 1/4 or 1.25

How to Use This Calculator

  1. Enter the numerator and denominator for the first fraction.
  2. Select the desired operation from the dropdown.
  3. Enter the numerator and denominator for the second fraction.
  4. Click "Calculate" to compute and automatically simplify the result.
  5. Use the Quick Reference table and example to verify your result.

Frequently Asked Questions

How do I find a common denominator?

Find the least common multiple (LCM) of the two denominators. For example, for 3/4 and 1/6, the LCM of 4 and 6 is 12, so you convert both to twelfths.

What is simplifying a fraction?

Simplifying means dividing both numerator and denominator by their greatest common divisor (GCD) until no common factors remain. For example, 6/8 simplifies to 3/4.

What is a proper vs. improper fraction?

A proper fraction has numerator less than denominator (less than 1). An improper fraction has numerator greater than or equal to denominator (1 or more). Both are valid.

What is a mixed number?

A mixed number combines a whole number and a fraction, like 1 3/4. It equals 1 + 3/4. This is useful for expressing improper fractions in everyday contexts.

Why is division of fractions done by multiplying by the reciprocal?

Division by a fraction is mathematically equivalent to multiplication by its reciprocal. This rule preserves properties of division and makes computation simpler.

Can I add fractions with different denominators directly?

No. You must convert to a common denominator first. Adding/subtracting denominators directly is a common mistake that produces incorrect results.

What happens if I have a zero denominator?

Division by zero is undefined in mathematics. A fraction with zero denominator is impossible and has no value. Always check that your denominator is non-zero.

How do I know if a fraction is fully simplified?

A fraction is fully simplified when the greatest common divisor of the numerator and denominator is 1 (they share no common factors other than 1).

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