Fraction Calculator
Add, subtract, multiply or divide fractions and mixed numbers, with the working shown.
About this tool
Enter fractions such as 3/4, mixed numbers such as 1 1/2, whole numbers or decimals. The answer is always simplified and also shown as a mixed number and a decimal, with the steps.
Work out fraction sums for homework, recipes, sewing, woodwork or measurements. Type two fractions or mixed numbers, choose add, subtract, multiply or divide, and get the simplified answer, the mixed number and the decimal, with the steps shown so you can check your own working. It runs in your browser.
How to use the Fraction Calculator
- Type the first fraction, for example 3/4 or 1 1/2 (a space between the whole number and the fraction).
- Choose add, subtract, multiply or divide.
- Type the second fraction.
- Read the simplified answer, the mixed number, the decimal and the working.
Adding 1/2 and 1/3
The denominators differ, so use a common denominator of 2 × 3 = 6: 1/2 = 3/6 and 1/3 = 2/6. Adding gives 5/6, which cannot be simplified, about 0.833333. As another check, 1 1/2 ÷ 3/4 becomes 3/2 × 4/3 = 12/6 = 2, and 3/4 − 1 1/2 = −3/4.
The rules for fractions
To add or subtract, the fractions need the same denominator: multiply each fraction top and bottom so they match, then add or subtract the numerators. To multiply, multiply the numerators together and the denominators together. To divide, flip the second fraction and multiply. Mixed numbers are turned into improper fractions first, so 1 1/2 becomes 3/2. Finally the answer is simplified by dividing the top and bottom by their greatest common divisor, so 6/8 becomes 3/4. A common mistake is adding the denominators: 1/2 + 1/3 is 5/6, not 2/5.
Frequently asked questions
How do I add fractions with different denominators?
Find a common denominator, convert both fractions, then add the numerators. For 1/4 + 1/6, use 12: 3/12 + 2/12 = 5/12.
How do I divide fractions?
Keep the first fraction, flip the second and multiply. 2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6.
How do I enter a mixed number?
Type the whole number, a space and the fraction, for example 2 3/4. You can also type a decimal such as 2.75.
How do I simplify a fraction?
Divide the top and bottom by the largest number that goes into both. 18/24 divides by 6 to give 3/4. Type the fraction, choose multiply and enter 1 as the second number to simplify it here.