Fraction Calculator

Fraction Calculator

Add, subtract, multiply, or divide any two fractions and get the result automatically simplified to its lowest terms. This calculator also shows the decimal equivalent, making it useful for students learning fractions, cooks adjusting recipes, and builders working with fractional measurements.

How Fraction Arithmetic Works

Each operation follows standard fraction rules. Addition/Subtraction: find a common denominator, then add or subtract numerators: (a/b) + (c/d) = (ad + bc) / bd. Multiplication: multiply straight across: (a/b) x (c/d) = ac / bd. Division: flip the second fraction and multiply: (a/b) / (c/d) = ad / bc. Results are simplified using the greatest common divisor (GCD).

Example

Key Factors in Fraction Calculations

• Common denominator — addition and subtraction require finding a common denominator; this calculator handles it automatically
• Simplification — results are always reduced using the GCD (e.g., 6/8 becomes 3/4)
• Sign handling — negative fractions are supported; the sign is applied to the numerator
• Zero denominator — entering zero as a denominator is undefined and will produce an error message

Tips

1. For recipe scaling, multiply the ingredient fraction by the scaling factor — e.g., 3/4 cup x 2/3 = 1/2 cup
2. When adding fractions with the same denominator, just add the numerators directly
3. Use this calculator to check homework — enter the problem and verify your hand-calculated answer matches
4. Remember that dividing by a fraction is the same as multiplying by its reciprocal