Fraction Calculator
Add, subtract, multiply, or divide two fractions. Mixed numbers like 1 1/2 and decimals like 0.75 are accepted, and every result is shown in lowest terms.
Add, subtract, multiply or divide fractions and mixed numbers. Accepts 3/4, 1 1/2, decimals, or whole numbers.
The four rules of fraction arithmetic
Every fraction problem reduces to one of four operations. The mechanics of each are simple but easy to mix up:
- Addition and subtraction require a common denominator. Multiply each fraction by what it needs to reach the lowest common denominator, then add or subtract numerators.
- Multiplication is the easiest: multiply numerator by numerator, denominator by denominator, then simplify.
- Division is multiplication by the reciprocal: flip the second fraction and multiply.
The calculator above shows every one of these steps in order, so the result is never a black box.
Why simplify?
An unsimplified answer like 12/16 is technically correct but wrong by convention — school marking schemes will deduct points. The calculator divides numerator and denominator by their greatest common divisor automatically, so you always get 3/4 as the canonical form.
Mixed numbers
A mixed number such as 2 3/4 represents two whole units plus three quarters. The calculator accepts mixed numbers as input and also displays results that way when the numerator exceeds the denominator. Internally everything is stored as an improper fraction so the arithmetic is exact.