Fraction Calculator — Exact Arithmetic

What it does

Combine two fractions or integers and view the answer as a reduced fraction and a mixed number. Exact integer arithmetic preserves the numerator and denominator, including integers larger than JavaScript’s usual safe-number range. The tool is useful for checking fraction exercises or quantities already expressed as fractions.

How to use

1. Enter each operand as an integer or numerator/denominator, such as 2 or -7/3.
2. Choose addition, subtraction, multiplication or division.
3. Calculate and copy the reduced fraction or mixed-number result.

Calculation rules and limits

• Each numerator and denominator accepts up to 100 decimal digits with an optional sign.
• Decimal input such as 0.5 is not accepted; enter 1/2 instead.
• A denominator of zero is invalid, and division by a zero fraction is undefined.
• Results are reduced by the greatest common divisor and the denominator is kept positive. A negative mixed number such as -2 1/3 means -(2 + 1/3).

Example

1/3 + 1/6 = 1/2. Multiplying 2/3 by 9/4 produces 3/2, or 1 1/2. Dividing -7/3 by 1 produces -7/3, or -2 1/3.

Calculations run in your browser without uploading your calculation data. Changing an input clears the previous result; choose Calculate again to get the updated answer.