Free Fraction Calculator Online
This free online fraction calculator adds, subtracts, multiplies, or divides any two fractions. Results are automatically simplified to lowest terms.
Enter Fractions
Result
Enter fractions and click Calculate.
Fraction Arithmetic Rules
| Operation | Formula | Example |
|---|---|---|
| Addition (a/b + c/d) | (a×d + c×b) / (b×d) | 1/3 + 1/4 = (4+3)/12 = 7/12 |
| Subtraction (a/b − c/d) | (a×d − c×b) / (b×d) | 3/4 − 1/3 = (9−4)/12 = 5/12 |
| Multiplication (a/b × c/d) | (a×c) / (b×d) | 2/3 × 3/4 = 6/12 = 1/2 |
| Division (a/b ÷ c/d) | (a×d) / (b×c) | 1/2 ÷ 1/4 = 4/2 = 2 |
How This Free Fraction Calculator Works
A free online fraction calculator needs to handle three things correctly: finding a common denominator (for addition and subtraction), applying the arithmetic rule, and simplifying the result. This fraction calculator does all three automatically.
For addition and subtraction, the fraction calculator uses cross multiplication to find a valid common denominator. For multiplication, it multiplies straight across. For division, it flips the second fraction (reciprocal) and multiplies. Every result is reduced using the Greatest Common Divisor (GCD) so you always see the simplest form. Use it free of charge — no account required.
The free fraction calculator also shows the decimal equivalent, which is useful when you need to compare a fraction result to a decimal context — like a measurement, a price, or a percentage. Calculate online instantly and get simplified results every time.
When You Need a Fraction Calculator
Cooking & Recipes
Scaling a recipe from 4 servings to 6 means multiplying every measurement by 3/2. If a recipe calls for 2/3 cup of flour, you need 2/3 × 3/2 = 1 cup. This free fraction calculator handles these conversions in seconds with no risk of arithmetic error.
Construction & DIY
Measurements in woodworking and construction are often in fractions of an inch — 3/8", 5/16", 7/32". Adding them requires a common denominator. Our free online fraction calculator is faster and more reliable than doing it by hand.
Homework & School
Fractions appear throughout elementary through college-level math — ratios, proportions, algebraic fractions. Using a free fraction calculator online to check your work helps you verify steps without needing to simplify manually every time.
Fraction Tips & Tricks
Always Simplify First
Before multiplying, cross-simplify: cancel common factors between any numerator and any denominator. Example: (2/3) × (9/4) — cancel the 3 and 9 to get (2/1) × (3/4) = 6/4 = 3/2.
Convert Mixed Numbers First
Turn 2 1/3 into 7/3 before entering it. Multiply the whole number by the denominator and add the numerator: (2×3 + 1)/3 = 7/3.
Division = Multiply by Reciprocal
Dividing by a fraction is the same as multiplying by its flip. So 3/4 ÷ 2/5 is the same as 3/4 × 5/2 = 15/8. Use this free tool online — the fraction calculator does this automatically for the ÷ operator.
GCD Is the Key to Simplification
To simplify 18/24: find GCD(18,24) = 6, then divide both by 6 to get 3/4. The fraction calculator uses this algorithm automatically for every result.
Frequently Asked Questions
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