Add, subtract, multiply and divide fractions
Built & maintained by Pappu Venkata Subbi Reddy, founder of Clacify · Updated August 2026
Fraction Calculator adds, subtracts, multiplies, and divides fractions — and shows the steps. Enter two fractions (proper, improper, or mixed numbers) and an operation to get the answer, automatically simplified to its lowest terms and shown as both an improper fraction and a mixed number. It's built for students learning fractions, parents helping with homework, and anyone who needs a quick, accurate fraction answer without doing the arithmetic by hand. Working is shown so you can learn, not just copy.
Fractions are computed with exact integer arithmetic to avoid rounding errors: addition and subtraction use a common denominator (a/b ± c/d = (ad ± cb)/bd), multiplication multiplies numerators and denominators, and division multiplies by the reciprocal. The result is reduced using the greatest common divisor (GCD) and converted to a mixed number when improper. Mixed-number inputs are first converted to improper fractions. Every numerator-and-denominator operation above is worked out in JavaScript the instant you type, with no fraction ever leaving your device.
| Operation | Example | Steps | Result |
|---|---|---|---|
| Addition | 1/4 + 1/6 | LCD 12 → 3/12 + 2/12 | 5/12 |
| Subtraction | 3/4 − 1/6 | LCD 12 → 9/12 − 2/12 | 7/12 |
| Multiplication | 2/3 × 3/5 | (2×3)/(3×5) = 6/15 | 2/5 (simplified ÷3) |
| Division | 2/3 ÷ 3/5 | flip and multiply: 2/3 × 5/3 = 10/9 | 1 1/9 |
Every result is shown fully simplified — the calculator does this same reduction step automatically for any two fractions you enter.
To add or subtract fractions, both must count the same-sized "slices" — that's the common denominator. The reliable way to find it is the Lowest Common Multiple (LCM) of the two denominators, not just multiplying them together (which works but often leaves a bigger, unsimplified fraction to reduce afterward). For 1/4 and 1/6, the LCM of 4 and 6 is 12, so both fractions convert to twelfths before adding.
Dividing by a fraction is the same as multiplying by its reciprocal (flip the numerator and denominator) — because dividing by 3/5 is asking "how many 3/5-sized pieces fit into this," which is mathematically identical to multiplying by 5/3. That's why 2/3 ÷ 3/5 becomes 2/3 × 5/3 rather than a direct division.
An improper fraction (numerator larger than denominator, like 10/9) converts to a mixed number by dividing: 10 ÷ 9 = 1 remainder 1, so 10/9 = 1 whole and 1/9 left over, written 1 1/9. Going the other way, a mixed number converts to improper by multiplying the whole number by the denominator and adding the numerator — 1 1/9 becomes (1×9 + 1)/9 = 10/9. The calculator does this conversion automatically on the way in and the way out.
To add fractions with different denominators: (1) Find the LCM of the denominators. (2) Convert each fraction to an equivalent fraction with the LCM as denominator. (3) Add the numerators. (4) Simplify. Example: 1/3 + 1/4 → LCM = 12 → 4/12 + 3/12 = 7/12.
Divide the numerator by the denominator. For example: 3/4 = 3 ÷ 4 = 0.75. 1/3 = 0.333... (repeating decimal). 7/8 = 0.875. Some fractions produce terminating decimals (denominators with only factors of 2 and 5); others produce repeating decimals.