Fraction Calculator

Fraction Calculator adds, subtracts, multiplies and divides two fractions, whole numbers or mixed numbers using exact big-integer arithmetic. Every answer is reduced to lowest terms and shown as an improper fraction, a mixed number where it applies, and a decimal, together with the steps used to get there.

Fraction arithmetic is easy to slip on: finding a common denominator, flipping the divisor or simplifying the result. Seeing each step makes it simple to check homework, recipes, measurements and woodworking cuts, and exact arithmetic means no rounding creeps in.

1. Enter the first value as a whole number (7), a fraction (3/4) or a mixed number (2 1/3).
2. Choose add, subtract, multiply or divide.
3. Enter the second value.
4. Press Calculate to see the simplified fraction, mixed number and decimal.
5. Read the steps, then copy or download the summary.

• Addition, subtraction, multiplication and division
• Whole numbers, proper and improper fractions, negative fractions and mixed numbers
• Exact BigInt arithmetic with results in lowest terms
• Improper fraction, mixed number and 12-place decimal forms
• Step-by-step working, including the common denominator and the reciprocal
• Clear errors for zero denominators, division by zero, malformed mixed numbers and oversized input

• Type mixed numbers with a space between the whole number and the fraction: 2 1/3.
• Put a minus sign only at the front of a value, for example −3/4 or −1 1/2.
• Use the mixed-number form for measurements and the improper fraction for further calculations.
• Treat the decimal as a convenience — the fraction is the exact answer.