Fraction Calculator

Struggling with fractions? This calculator handles addition, subtraction, multiplication, and division of any fractions — and automatically simplifies the result to its lowest terms.

How to Use This Calculator

1. Enter the first fraction (numerator and denominator).
2. Select the operation: +, −, ×, ÷.
3. Enter the second fraction.
4. Click Calculate to get the simplified result, shown as both a fraction and mixed number if applicable.

Fraction Operation Rules

Addition/Subtraction: Find common denominator, then add/subtract numerators.
Example: 1/3 + 1/4 = 4/12 + 3/12 = 7/12

Multiplication: Multiply numerators together, multiply denominators together.
Example: 2/3 × 3/5 = 6/15 = 2/5 (simplified)

Division: Multiply by the reciprocal (flip the second fraction).
Example: 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8 = 1 7/8 (mixed number)

Simplification

A fraction is in lowest terms when the GCF (greatest common factor) of numerator and denominator is 1. To simplify: divide both by their GCF. 12/18 → GCF is 6 → 2/3.

Common Mistakes to Avoid

• Adding denominators instead of finding common denominator — 1/3 + 1/4 ≠ 2/7. You must find the LCD (12) first.
• Forgetting to simplify — 6/8 and 3/4 are the same fraction; always reduce to lowest terms.
• Dividing by flipping the wrong fraction — In a ÷ b, flip the second fraction (b). Never flip the first fraction.

Frequently Asked Questions

How do I find the LCD?

The Least Common Denominator is the LCM of the denominators. For 1/3 and 1/4: LCM of 3 and 4 = 12. So LCD = 12. See our LCM Calculator.

How do I convert a mixed number to an improper fraction?

Multiply the whole number by the denominator, add the numerator. 2 3/4 = (2×4 + 3)/4 = 11/4.

What is a unit fraction?

A fraction where the numerator is 1 (1/2, 1/3, 1/7, etc.). Ancient Egyptians represented all fractions as sums of unit fractions.

Conclusion

Fractions are fundamental to math, cooking, construction, and everyday problem-solving. Use this calculator to work through any fraction problem instantly and double-check your manual calculations.

Related: Percent Calculator | Ratio Calculator | LCM Calculator | GCF Calculator