How to use it
Type two fractions, choose +, −, × or ÷, and the answer appears at once in simplest form, as a mixed number and as a decimal, with the steps below it. You can type 3/4, a mixed number such as 2 1/3, a whole number, or a decimal such as 0.125 (which is turned into 1/8). The second box below simplifies a single fraction and shows it as a mixed number, a decimal and a percent.
How the sums work
Adding and subtracting needs a common denominator (the bottom number): 1/2 + 1/3 becomes 3/6 + 2/6 = 5/6. Multiplying is top times top over bottom times bottom: 2/3 × 3/4 = 6/12 = 1/2. Dividing flips the second fraction and multiplies. Every answer is then divided by the greatest common divisor to reach lowest terms.
Questions
Is it exact? Yes. It uses whole-number arithmetic with no rounding, so even very large fractions stay exact. A repeating decimal such as 1/3 ends with …. Why can’t I divide by zero? It has no answer. Do I need to simplify first? No, the calculator does it. For percentages of a number, see the Percentage Calculator.