Math

Adding Fractions Calculator

Add Fractions with Different Denominators in Seconds

Enter two fractions and instantly see their sum, fully simplified with every intermediate step shown. The calculator finds the least common denominator (LCD), converts each fraction, adds the numerators, and reduces the result to lowest terms. Toggle mixed number mode to work with values like 2 1/3 + 1 3/4.

Tips

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Try an Example

Pick a scenario to see how the calculator works, then adjust the values

Add Fractions

Add 1/2 + 1/3 and see the step-by-step solution.

Key values: 1/2 + 1/3 · Common denominators · Simplified result

Simplify a Fraction

Reduce 24/36 to its simplest form using GCD.

Key values: 24/36 · GCD method · Lowest terms

Decimal to Fraction

Convert 0.75 to a fraction and see the work.

Key values: 0.75 · Fraction conversion · Simplified

Mixed Number Division

Divide 2 1/4 by 1 1/2 with mixed number support.

Key values: 2 1/4 ÷ 1 1/2 · Mixed numbers · Step-by-step

Documentation

This calculator is also known as Adding Fractions Calculator.

Read the complete guide

How to Add Fractions

Adding fractions requires a common denominator before the numerators can be combined.

If the denominators are the same, add the numerators directly
If the denominators differ, find the least common denominator (LCD)
Convert each fraction to an equivalent fraction with the LCD
Add the numerators and keep the LCD as the denominator
Simplify the result by dividing by the GCD

Examples

Adding 1/3 + 1/4

A student needs to solve 1/3 + 1/4 for homework.

LCD = 12. Convert: 4/12 + 3/12 = 7/12. Already in simplest form.

Key takeaway: 1/3 + 1/4 = 7/12.

Tips for Adding Fractions

Build speed and accuracy when adding fractions:

Memorize the LCMs of common denominator pairs (3 & 4 = 12, 6 & 8 = 24) to skip the calculation step
Always simplify the result -- check whether the GCD of the new numerator and denominator is greater than 1
For mixed numbers, convert to improper fractions first rather than adding whole parts and fraction parts separately
Use the step-by-step panel to verify your own work before submitting homework

Frequently Asked Questions about Adding Fractions Calculator

How do you add fractions with different denominators?

Find the least common denominator (LCD), convert each fraction so both share that denominator, then add the numerators. For example, 1/3 + 1/4: LCD is 12, so 4/12 + 3/12 = 7/12.

What is the LCD?

The LCD (least common denominator) is the smallest number that both denominators divide into evenly. It equals lcm(b, d) = |b * d| / gcd(b, d).

Can I add mixed numbers?

Yes. Toggle "Use Mixed Numbers" to enter values like 2 1/3. The calculator converts them to improper fractions, performs the addition, and converts the result back.