Fraction Calculator: Add, Subtract, Multiply and Divide Fractions
This fraction calculator adds, subtracts, multiplies and divides fractions and mixed numbers. Enter two fractions, pick an operation, and get the answer in its simplest form, as a mixed number and as a decimal, with the working shown step by step.
Leave the whole-number box empty for a simple fraction. For a mixed number like 1 2/3, fill all three boxes.
Steps
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Quick answer: To add fractions, give them the same denominator, add the numerators and simplify: 3/4 + 1 2/3 = 9/12 + 20/12 = 29/12 = 2 5/12. The calculator above does every step for you.
How to use the fraction calculator
- Enter the first fraction: the top box is the numerator, the bottom box the denominator. Add a whole number on the left for a mixed number.
- Choose +, −, × or ÷.
- Enter the second fraction. The answer, mixed number, decimal and steps update instantly.
For a negative fraction, put the minus sign on the whole number, or on the numerator if there is no whole number.
Fraction rules in brief
- Adding and subtracting: find a common denominator (the least common multiple of the two), convert both fractions, then add or subtract the numerators.
- Multiplying: multiply the numerators together and the denominators together.
- Dividing: flip the second fraction (its reciprocal) and multiply. “Keep, change, flip.”
- Simplifying: divide the top and bottom by their greatest common divisor. 18/24 becomes 3/4 by dividing both by 6.
- Mixed numbers: turn 2 1/3 into an improper fraction by multiplying 2 × 3 and adding 1, giving 7/3.
How to simplify fractions
To simplify a single fraction, enter it as the first fraction, choose ×, and enter 1/1 as the second. The result is the fraction in lowest terms. A fraction is fully simplified when the only number that divides both top and bottom is 1.
Common fractions as decimals
| Fraction | Decimal | Fraction | Decimal |
|---|---|---|---|
| 1/2 | 0.5 | 1/8 | 0.125 |
| 1/3 | 0.333… | 3/8 | 0.375 |
| 2/3 | 0.666… | 1/5 | 0.2 |
| 1/4 | 0.25 | 1/10 | 0.1 |
| 3/4 | 0.75 | 1/16 | 0.0625 |
Need percentages instead? Try the percentage calculator. For averages, use the average calculator.
FAQ
Can I use this for recipes?
Yes. To double 3/4 cup, multiply 3/4 by 2/1 to get 1 1/2 cups.
How do I enter a whole number?
Type it in the whole-number box and leave the numerator empty.
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