Fraction Calculator

Add, subtract, multiply or divide two fractions or mixed numbers. You get the answer in lowest terms, as a mixed number, a decimal and a percentage, with the working shown.

Boxes: whole number, numerator over denominator. For 2 3/4 type 2, 3 and 4. For a plain fraction leave the whole box empty.

Answer

Fraction: 5/6
Mixed number: 5/6
Decimal: 0.833333

As a percentage: 83.3333%

Show working

As improper fractions: 1/2 + 1/3
Common denominator: (1 × 3 + 1 × 2) / (2 × 3)
= 5 / 6
Simplify to lowest terms: 5/6

Calculated instantly in your browser with standard formulas. Double-check anything important. Full disclaimer and terms of use.

How to add and subtract fractions

To add or subtract fractions, give them the same denominator. Multiply the top and bottom of each fraction by the other fraction's denominator, add or subtract the numerators, and keep the new denominator. Then simplify. For 3/4 − 5/8: 6/8 − 5/8 = 1/8.

How to multiply and divide fractions

Multiply: multiply the numerators together and the denominators together. 2/3 × 3/4 = 6/12 = 1/2.
Divide: flip the second fraction (swap its top and bottom) and multiply. 2/3 ÷ 3/4 = 2/3 × 4/3 = 8/9.
Mixed numbers: first turn them into improper fractions. 2 1/2 = 5/2.

Simplifying and converting

Simplify by dividing the top and bottom by the same number until nothing more divides both (their greatest common factor).
Improper to mixed number: divide the top by the bottom. 11/4 is 2 with a remainder of 3, so 2 3/4.
Fraction to decimal: divide the top by the bottom. 3/8 = 0.375.
Decimal to percentage: multiply by 100. 0.375 = 37.5%.

Common fractions as decimals and percentages

Fraction	Decimal	Percentage
1/2	0.5	50%
1/3	0.3333	33.33%
1/4	0.25	25%
1/5	0.2	20%
1/8	0.125	12.5%
3/4	0.75	75%
2/3	0.6667	66.67%

Where fractions are used

Cooking and baking, when you scale a recipe up or down.
Measuring and building, with inches and tape measures.
Maths homework, ratios, probabilities and percentages.

How to use the Fraction Calculator tool

Type the first fraction. Use the first box for a whole number if it is a mixed number such as 2 3/4.
Choose add, subtract, multiply or divide.
Type the second fraction.
Read the simplified answer, the mixed number, the decimal and the percentage, and open "Show working" for the steps.

Frequently asked questions

How do I add fractions with different denominators?

Give them a common denominator, add the numerators, then simplify. For 1/2 + 1/3: 1/2 = 3/6 and 1/3 = 2/6, so the sum is 5/6.

How do I multiply and divide fractions?

To multiply, multiply the numerators and the denominators: 2/3 × 3/4 = 6/12 = 1/2. To divide, flip the second fraction and multiply: 2/3 ÷ 3/4 = 2/3 × 4/3 = 8/9.

How do I enter a mixed number?

Type the whole number in the first box, then the numerator and denominator. For 2 3/4 enter 2, 3 and 4. For a negative mixed number put the minus sign on the whole number, for example -2 3/4.

What does simplifying a fraction mean?

It means dividing the top and bottom by their greatest common factor so the fraction is in lowest terms. 6/12 simplifies to 1/2. The calculator always shows the simplified answer.

Why can't I divide by zero?

Dividing by zero has no answer, and a fraction with a denominator of 0 is not defined, so the calculator asks you to change the numbers.