Fraction Calculator
Add, subtract, multiply, or divide any two fractions. Results are automatically simplified to lowest terms.
Fraction Operation
Result
5/6
Simplified Fraction
5/6
Decimal
0.833333
Percentage
83.3333%
How to Use This Calculator
Enter the numerator and denominator for each fraction, select the operation (add, subtract, multiply, or divide), and get the simplified result instantly. The calculator shows the simplified fraction and its decimal equivalent.
The Formulas
Addition: a/b + c/d = (a×d + c×b) / (b×d)
Subtraction: a/b − c/d = (a×d − c×b) / (b×d)
Multiplication: a/b × c/d = (a×c) / (b×d)
Division: a/b ÷ c/d = (a×d) / (b×c)
Simplification: divide numerator and denominator by their GCD
GCD = Greatest Common Divisor
Example
1/2 + 1/3
Step 1: Common denominator(1×3 + 1×2) / (2×3) = 5/6
GCD of 5 and 61 (already simplified)
Result5/6 = 0.8333...
FAQ
The GCD (Greatest Common Divisor) is the largest number that divides both the numerator and denominator evenly. For example, 12/18 — the GCD of 12 and 18 is 6, so 12÷6=2 and 18÷6=3, giving the simplified fraction 2/3. The Euclidean algorithm finds the GCD efficiently by repeatedly dividing and taking remainders.
To divide fractions, multiply the first fraction by the reciprocal (flip) of the second fraction. So 3/4 ÷ 2/5 becomes 3/4 × 5/2 = 15/8. This is the "keep, change, flip" method taught in Nigerian primary schools.
Convert mixed numbers to improper fractions first. For example, 2½ becomes 5/2 (multiply whole number by denominator and add numerator: 2×2+1=5). Enter 5 as numerator and 2 as denominator. The calculator handles any integers in the numerator and denominator fields.