Math calculator
Fraction Calculator
Add, subtract, multiply, or divide fractions with exact results.
Leave Whole blank for a simple fraction. Leave Numerator and Denominator blank for a whole number.
Exact result
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What is a fraction?
A fraction represents part of a whole. The numerator is the number above the line, and the denominator is the number below it. The denominator cannot be zero.
How fraction operations work
To add or subtract fractions, find a common denominator, then add or subtract the adjusted numerators. To multiply, multiply numerators and denominators. To divide, multiply by the reciprocal of the second fraction.
How fractions are simplified
The calculator divides the numerator and denominator by their greatest common divisor. This produces an equivalent fraction in lowest terms while preserving the exact value.
Mixed numbers and improper fractions
An improper fraction has a numerator at least as large as its denominator, such as 6/5. Its mixed-number form is 1 1/5. Enter a mixed number with the optional Whole, Numerator, and Denominator fields.
Worked examples
For 1/2 + 1/3, use denominator 6: 3/6 + 2/6 = 5/6.
For 4/5 ÷ 2/3, multiply by the reciprocal: 4/5 × 3/2 = 12/10 = 6/5 = 1 1/5.
Negative signs are normalized to the numerator, so −1/2 + 3/4 = 1/4.
Frequently asked questions
Can I enter a whole number?
Yes. Enter it in Whole and leave Numerator and Denominator blank. A blank denominator is treated as 1.
Why can't the denominator be zero?
Division by zero is undefined, so the calculator rejects zero denominators and division by a zero-valued fraction.
Are the exact results rounded?
No. Exact results use integer arithmetic. The decimal display shows up to 12 digits and adds an ellipsis when the decimal repeats or continues.