Calculadora de Fração
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
a/b + c/d = (a·d + c·b)/(b·d)
About this calculator
The Fraction Calculator is a free online tool that performs the four basic operations (addition, subtraction, multiplication, and division) between two fractions. Simply enter the numerators and denominators of the fractions and choose the desired operation. The result is displayed as a simplified fraction, making it easy to understand.
The operation is straightforward: for adding or subtracting fractions, the calculator uses the common denominator method. For example, a/b + c/d = (a·d + c·b)/(b·d). For multiplication, multiply numerator by numerator and denominator by denominator. For division, invert the second fraction and multiply. The result is then simplified by the greatest common divisor (GCD).
This calculator is useful for students, teachers, and professionals who need to solve fraction problems quickly. Common situations include cooking recipes, dividing materials, proportions in projects, and basic math exercises. It helps avoid manual errors and saves time.
Important precautions: always ensure denominators are non-zero, as division by zero is undefined. Also, the calculator automatically simplifies the resulting fraction, but it's good to check if the result makes sense in the problem context. Negative fractions are also supported.
Frequently asked questions
How do I add fractions with different denominators?
The calculator uses the common denominator method: a/b + c/d = (a·d + c·b)/(b·d). Just enter the values and select the addition operation.
What happens if I enter a denominator equal to zero?
The calculator will display an error message, as division by zero is not allowed. Ensure both denominators are non-zero.
Does the calculator simplify the result automatically?
Yes, the result is simplified by the greatest common divisor (GCD) of the numerator and denominator.
Can I use negative numbers in fractions?
Yes, the calculator accepts negative numerators and denominators, resulting in negative fractions when appropriate.
How do I divide fractions?
To divide a/b by c/d, the calculator inverts the second fraction (swapping numerator and denominator) and multiplies: (a/b) ÷ (c/d) = (a·d)/(b·c).