Precision Utility
Fraction
Calculator
Operations
4
Simplify
Auto
Add, subtract, multiply or divide any two fractions and get the answer simplified automatically. The calculator also converts your result to a decimal and percentage so you can use it however you need.
Enter Fractions
Result
3/4
Result Fraction
3/4
Decimal
0.75
Percentage
75%
Simplified
3/4
How the fraction calculator works
Enter the numerator and denominator for each fraction using the paired input fields. The "/" between them represents the fraction bar, so typing 3 and 4 gives you 3/4.
Choose your operation: addition, subtraction, multiplication or division. The calculator finds a common denominator where needed, performs the arithmetic and simplifies the result using the greatest common divisor (GCD).
Results update instantly as you type. You'll see the answer as a simplified fraction, its decimal equivalent and the percentage value, all calculated in real time.
What you need to know about fractions
Simplifying fractions. A fraction is in its simplest form when the numerator and denominator share no common factor other than 1. The calculator finds the GCD using the Euclidean algorithm and divides both parts automatically. For example, 8/12 becomes 2/3.
Mixed numbers. A mixed number like 2 3/4 can be converted to an improper fraction before calculating. Multiply the whole number by the denominator, add the numerator, and keep the same denominator: 2 3/4 = (2 x 4 + 3)/4 = 11/4. Enter 11 and 4 into the calculator to use it.
Common denominators. Addition and subtraction require fractions to share the same denominator. The calculator finds the lowest common denominator (LCD) by computing the least common multiple of the two denominators. Multiplication and division don't need a common denominator -- you multiply straight across or flip and multiply.
- Addition: a/b + c/d = (ad + bc) / bd, then simplify
- Subtraction: a/b - c/d = (ad - bc) / bd, then simplify
- Multiplication: a/b x c/d = ac / bd, then simplify
- Division: a/b / c/d = ad / bc, then simplify
Frequently asked questions
How do you add fractions with different denominators?
Find the lowest common denominator (LCD), convert each fraction so they share that denominator, then add the numerators. For example, 1/3 + 1/4: the LCD is 12, so 4/12 + 3/12 = 7/12.
How do you simplify a fraction?
Divide both the numerator and denominator by their greatest common divisor (GCD). For example, 8/12: the GCD of 8 and 12 is 4, so 8/12 simplifies to 2/3.
How do you multiply fractions?
Multiply the numerators together and the denominators together. For example, 2/3 x 4/5 = 8/15. Then simplify the result if possible.
How do you divide fractions?
Flip the second fraction (find its reciprocal) and multiply. For example, 2/3 / 4/5 = 2/3 x 5/4 = 10/12, which simplifies to 5/6.
What is a mixed number?
A mixed number combines a whole number with a proper fraction, such as 2 3/4. To use it in this calculator, convert it to an improper fraction first: multiply the whole number by the denominator, add the numerator, and keep the same denominator. So 2 3/4 becomes 11/4.
How do you convert a fraction to a decimal or percentage?
Divide the numerator by the denominator to get the decimal. Multiply the decimal by 100 to get the percentage. For example, 3/4 = 0.75 = 75%. This calculator does both conversions for you automatically.