Fraction Calculator
Fraction calculator: add, subtract, multiply or divide two fractions and get the answer in lowest terms.
Editorial review: Farrow (pseudonym; identity and professional credentials are not disclosed). This page is for educational purposes, not professional advice.
Your inputs
Results update as you type. Nothing you enter leaves your device.
Results
- Decimal
- 0.833333
Example with the starting values
These results use the calculator's initial inputs. Change the values above to calculate your own estimate.
Inputs
- Numerator 1
- 1
- Denominator 1
- 2
- Operation
- Add (+)
- Numerator 2
- 1
- Denominator 2
- 3
Results
- Result
- 5/6
- Decimal
- 0.833333
How does the Fraction Calculator work?
A fraction is a number written as a/b, where a is the numerator and b is the nonzero denominator. To add, a/b + c/d = (ad + bc) / bd; to multiply, a/b × c/d = ac / bd.
The calculator combines the fractions over a common denominator, then divides the numerator and denominator by their greatest common divisor to give lowest terms. For example, 1/2 + 1/3 = 3/6 + 2/6 = 5/6.
Frequently asked questions
How do I add fractions with different denominators?
Rewrite both over a common denominator, then add the numerators. For 1/4 + 2/3, use 12: 3/12 + 8/12 = 11/12.
How do I simplify a fraction?
Divide the numerator and denominator by their greatest common divisor. For 18/24, the GCD is 6, so 18/24 = 3/4.
How do I multiply fractions?
Multiply the numerators together and the denominators together, then simplify. For 2/3 × 3/4, you get 6/12, which simplifies to 1/2.
How do I divide fractions?
Multiply the first fraction by the reciprocal of the second: a/b ÷ c/d = (a·d)/(b·c).