Fraction Calculator
Add, subtract, multiply, or divide fractions with automatic simplification.
0.833333
Try an example
About this calculator
How This Fraction Calculator Works
Enter two fractions and pick an operation, and the calculator returns the result as a simplified fraction and its decimal equivalent.
The Rules by Operation
Adding and subtracting fractions requires a common denominator — this calculator cross-multiplies to find one automatically, so 1/2 + 1/3 becomes 3/6 + 2/6 = 5/6.
Multiplying fractions is direct: multiply the numerators together and the denominators together. 2/3 × 3/4 = 6/12, which simplifies to 1/2.
Dividing by a fraction is the same as multiplying by its reciprocal (flip the second fraction upside down, then multiply): 1/2 ÷ 1/4 becomes 1/2 × 4/1 = 4/2 = 2.
Every result is automatically reduced to its simplest form by dividing both the numerator and denominator by their greatest common factor.
Worked example
1/2 + 1/3 = (1×3 + 1×2) / (2×3) = 5/6, already in simplest form since 5 and 6 share no common factor — equivalent to 0.833333 as a decimal.
Frequently asked questions
How does this add fractions with different denominators?
It cross-multiplies to a common denominator first: a/b + c/d = (a×d + c×b) / (b×d), then simplifies the result to its lowest terms.
How does fraction division work?
Dividing by a fraction is the same as multiplying by its reciprocal: a/b ÷ c/d = a/b × d/c.
Why is my result automatically simplified?
The calculator divides both the numerator and denominator by their greatest common factor, so you always get the fraction in lowest terms rather than an unreduced one.
Can I enter negative fractions?
Yes — a negative numerator or denominator is handled correctly and the sign carries through to the simplified result.