Free Fraction Calculator (+ Guide)

What is a fraction calculator?

A fraction calculator does arithmetic with fractions and gives the answer as a fraction, not just a decimal.

This one also reads mixed numbers like 1 1/2 and decimals like 0.75, which it turns into exact fractions (3/4).

How fraction math works

Each operation has its own rule.

Adding and taking away

Fractions can only be added when their bottoms match. So you find the lowest common denominator, the smallest number both bottoms go into, and rewrite each fraction over it.

Multiplying

Multiply the tops together and the bottoms together. No common denominator needed.

Dividing

Dividing by a fraction is the same as multiplying by it upside down. So 3/4 ÷ 2/3 becomes 3/4 × 3/2.

A worked example

Here's the example the calculator loads: 1/2 + 1/3.

The lowest common denominator of 2 and 3 is 6. So 1/2 = 3/6 and 1/3 = 2/6, and 3/6 + 2/6 = 5/6.

5/6 is already in lowest terms. As a decimal it's 0.8333, or 83.33%.

Mistakes to avoid

These are the slips that cost marks.

• Adding the bottoms: 1/2 + 1/3 isn't 2/5
• Flipping the first fraction when dividing instead of the second
• Forgetting to simplify: 6/12 should be 1/2
• Dropping the 1 in 1 1/2 before converting a mixed number

Who is the fraction calculator for?

It's for students, parents checking homework, and anyone scaling a recipe, and these tools help around it.

• Percentage calculator – for a fraction as a percent of something
• Scientific calculator – for anything beyond fractions
• Grade calculator – for your grade from your scores

Show the steps, and the answer takes care of itself.