About this tool
The Mixed Number Calculator performs exact arithmetic on mixed numbers, improper fractions, and whole numbers. Each operand entered as 'A B/C' (a whole part plus a fraction), 'B/C', or a plain integer is first converted to an improper fraction with numerator A·C + B (carrying the sign) over C. Addition and subtraction bring both fractions to a common denominator L = lcm(d₁, d₂) and combine the numerators; multiplication multiplies numerators and denominators; division multiplies by the reciprocal of the second operand.
The result is reduced to lowest terms by dividing numerator and denominator by their greatest common divisor via the Euclidean algorithm, then converted back to a mixed number: the whole part is the integer quotient and the remainder becomes the new fraction. Every step — convert, common denominator, combine, reduce, and convert back — is shown so the working is easy to follow.
All arithmetic uses JavaScript BigInt integers, so there is no floating-point error even with large numerators and denominators, and everything runs locally in your browser. Enter two operands, choose +, −, ×, or ÷, and read the answer as a reduced mixed number, an equivalent improper fraction, and a decimal.