Fraction Calculator

Fractions remain a cornerstone of quantitative reasoning, and this tool handles all four basic operations—addition, subtraction, multiplication, and division—while returning exact, fully reduced results. The skill is far from academic: fractional thinking shows up everywhere from reading investment portfolios to scaling recipes. Students, teachers, and working professionals can lean on it to clear away tedious arithmetic and focus on the problem itself.

The math behind each operation follows standard arithmetic. For addition and subtraction the calculator cross-multiplies, using the product of the two denominators as the common denominator (a/b + c/d = (ad + cb)/bd), and shows that fraction in the Unsimplified row. By hand, the least common multiple (LCM) of the denominators keeps the numbers smaller; both routes reduce to the same answer. Multiplication is more direct—numerators multiply together and denominators multiply together—while division flips the second fraction and multiplies. Every answer is then reduced to lowest terms, recast as a mixed number where that makes sense, and shown as a decimal so you can read the result whichever way suits you.

Each fraction is entered as a numerator and a denominator, both whole numbers, so convert mixed numbers to improper fractions first: 1 1/2 is 3/2, not 11/2. The tool simplifies automatically, but it helps to know why a result reduces the way it does, since that intuition transfers to mental math. Watch the denominators as well: division by zero has no defined value, so the calculator shows no result when a denominator is 0 or when you divide by a fraction whose numerator is 0.