Fraction Calculator
This fraction calculator adds, subtracts, multiplies, and divides fractions, and it works with mixed numbers too. Pick an operation, type your two fractions, and you'll get the answer in its simplest form, along with the decimal, the percent, and a picture of the fraction. Every result shows the steps, so it's easy to learn the how, not just the what.
- Add, subtract, multiply, divide
- Mixed numbers
- Auto-simplified
- Decimal and percent
- Steps shown
Last updated June 16, 2026 Add, subtract, multiply, divide Reviewed by the Calcowa math team
Leave the small box empty for a simple fraction, or use it for a mixed number.
Enter both fractions with a bottom number that isn't zero.
1/2 + 1/3 = 3/6 + 2/6 = 5/6
What is a fraction?
A fraction is a part of a whole, written as a top number over a bottom number. The bottom, the denominator, says how many equal pieces the whole is cut into, and the top, the numerator, says how many of those pieces you have. So 3/4 means three out of four equal pieces, and that's all a fraction is. Once you've pictured it that way, the four operations all make sense.
How to add and subtract fractions
To add or subtract fractions, the bottoms have to match first. Find a common denominator, rewrite both fractions over it, then add or subtract the top numbers and keep the bottom the same. For 1/2 + 1/3, the common bottom is 6, so they become 3/6 and 2/6, which add to 5/6. The calculator picks the common denominator and reduces the answer for you, so you don't have to hunt for it, and the steps show every move.
How to multiply and divide fractions
Multiplying's the easy one: multiply the tops together and the bottoms together, then simplify. So 2/3 × 3/5 is 6/15, which reduces to 2/5, and the denominators don't need to match. Dividing is almost as quick. Here's the trick: flip the second fraction and multiply. To work out 1/2 ÷ 1/4, turn it into 1/2 × 4/1 = 2. It's the "keep, change, flip" rule, and the tool applies it automatically.
Simplifying and mixed numbers
A fraction's in its simplest form when the top and bottom share no common factor other than 1. You simplify by dividing both by their greatest common factor, so 6/8 becomes 3/4. When a fraction's bigger than one, like 7/4, it can also be written as a mixed number, 1 3/4, with a whole part and a leftover fraction. This calculator always simplifies the answer and shows the mixed number when there is one, so you don't have to do that last step by hand.
Fraction to decimal and percent
Every fraction's also a division, so you can turn it into a decimal by dividing the top by the bottom. That makes 3/4 into 3 ÷ 4 = 0.75, and multiplying by 100 gives 75%. The result above shows the decimal and the percent next to the fraction, which is handy when you're after the same value in a different form. For a quick percent of any number, the percentage calculator takes it from there.
The four operations
| Operation | Example | Answer | The rule |
|---|---|---|---|
| Add | 1/2 + 1/3 | 5/6 | Make the denominators match, then add the tops |
| Subtract | 3/4 − 1/2 | 1/4 | Match denominators, then subtract the tops |
| Multiply | 2/3 × 3/5 | 2/5 | Multiply the tops and the bottoms |
| Divide | 1/2 ÷ 1/4 | 2 | Flip the second fraction and multiply |
Frequently asked questions
Why do you need a common denominator to add fractions?
Because the pieces have to be the same size before you can count them together. Halves and thirds are different-sized pieces, so you rewrite both as sixths first, and then adding the tops actually means something.
Give both fractions the same bottom number, add the top numbers, and keep the bottom the same. For 1/2 + 1/3, rewrite them as 3/6 and 2/6, then add to get 5/6. It's that simple once the bottoms match, and the calculator finds the common denominator for you and simplifies the answer.
Multiply the top numbers together and the bottom numbers together, then simplify. So 2/3 × 3/5 is (2 × 3) over (3 × 5) = 6/15, which simplifies to 2/5. There's no need to match denominators when you multiply.
Flip the second fraction upside down and multiply. To do 1/2 ÷ 1/4, turn it into 1/2 × 4/1 = 4/2 = 2. People remember it as "keep, change, flip": keep the first, change divide to multiply, flip the second.
Divide the top and bottom by their greatest common factor. For 6/8, the largest number that divides both is 2, so it becomes 3/4. This calculator always gives the answer in its simplest form, and as a mixed number when it's bigger than one.
A mixed number is a whole number next to a fraction, like 1 1/2. It's the same value as the improper fraction 3/2. Type a whole number in the box on the left of either fraction, and the answer shows the mixed number too.
Divide the top by the bottom to get the decimal, so 3/4 is 3 ÷ 4 = 0.75. Multiply that by 100 for the percent, which makes 75%. The result here shows the decimal and the percent next to the fraction, so you've got every form at once.
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