Fraction Calculator: Add, Subtract, Multiply & Divide
To add or subtract fractions, first convert them to a common denominator. To multiply, multiply straight across. To divide, multiply by the second fraction flipped upside down. This calculator shows every step and simplifies the result.
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Result
5/6
≈ 0.8333
Show the math
- 1
Find a common denominator
LCM(2, 3) = 6
Both fractions need the same denominator before they can be combined.
= 6
Read the steps as text
- Find a common denominator. LCM(2, 3) = 6 Both fractions need the same denominator before they can be combined.
- Rewrite both fractions over it. 1/2 = 3/6 · 1/3 = 2/6
- Add the numerators. 3 + 2 = 5
Adding and subtracting: find a common denominator first
Fractions can only be added or subtracted directly when they share the same denominator. The calculator finds the lowest common multiple (LCM) of the two denominators, rewrites both fractions over it, then adds or subtracts the numerators.
For example, 1/2 + 1/3: the LCM of 2 and 3 is 6, so 1/2 becomes 3/6 and 1/3 becomes 2/6, giving 3/6 + 2/6 = 5/6.
Multiplying, dividing, and simplifying
Multiplying fractions needs no common denominator — multiply the numerators together and the denominators together. Dividing by a fraction is the same as multiplying by its reciprocal (flipped upside down): dividing by 2/3 is the same as multiplying by 3/2.
Every result is automatically simplified by dividing both numerator and denominator by their greatest common divisor (GCD), so an answer like 4/8 is shown as its simplest form, 1/2.
Frequently asked questions
- How do you add fractions with different denominators?
- Find the lowest common multiple of both denominators, rewrite each fraction over it, then add the numerators. The denominator stays the same.
- How do you divide fractions?
- Multiply the first fraction by the second fraction's reciprocal (flip its numerator and denominator), then multiply straight across.
- Why is my answer already simplified?
- This calculator automatically divides the result's numerator and denominator by their greatest common divisor, so you always see the simplest equivalent fraction.