Fraction calculator
Leave the whole number box empty for a plain fraction. Use it for mixed numbers like 1 ½.
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Simplify a fraction
Reduce a fraction to its lowest terms and convert it to a decimal and percentage.
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How to add, subtract, multiply and divide fractions
A fraction shows a part of a whole. The top number is the numerator and the bottom number is the denominator. This calculator works with proper fractions, improper fractions and mixed numbers.
Adding and subtracting
Fractions need a common denominator before you can add or subtract them. A simple way is to cross-multiply:
Example: 1/2 + 3/4 = (1 × 4 + 3 × 2) ÷ (2 × 4) = 10/8, which simplifies to 5/4, or 1 1/4.
Multiplying
Multiply the numerators together and the denominators together.
Example: 2/3 × 3/5 = 6/15, which simplifies to 2/5.
Dividing
Flip the second fraction upside down (take its reciprocal) and multiply.
Example: 1/2 ÷ 3/4 = (1 × 4) ÷ (2 × 3) = 4/6, which simplifies to 2/3.
Simplifying a fraction
Divide the numerator and denominator by their greatest common factor. For 18/24 the greatest common factor is 6, so 18/24 = 3/4.
Mixed numbers
A mixed number such as 1 1/2 is a whole number plus a fraction. To calculate with it, convert it to an improper fraction first: (1 × 2 + 1) ÷ 2 = 3/2. The calculator does this for you and shows the step.