Fraction
Calculator

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 will see the answer as a simplified fraction, its decimal equivalent and the percentage value, all calculated in real time.

The key to working with fractions is understanding each step. Here are four common problems solved step by step, covering each operation.

These are the fraction calculations people search for most often. Each answer includes the simplified fraction, decimal and percentage.

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 × 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 do not need a common denominator — you multiply straight across or flip and multiply.

Equivalent fractions. Two fractions are equivalent if they represent the same value. For example, 2/4, 3/6 and 4/8 are all equivalent to 1/2. You can create equivalent fractions by multiplying or dividing both the numerator and denominator by the same number. Our ratio calculator works with the same principle of proportional equivalence.

Improper fractions and mixed numbers. When the numerator is larger than the denominator (like 7/4), the fraction is called improper. To convert to a mixed number, divide the numerator by the denominator: 7 ÷ 4 = 1 remainder 3, so 7/4 = 1 3/4. Both forms are mathematically correct.

• Addition: a/b + c/d = (ad + bc) / bd, then simplify
• Subtraction: a/b − c/d = (ad − bc) / bd, then simplify
• Multiplication: a/b × c/d = ac / bd, then simplify
• Division: a/b ÷ c/d = ad / bc, then simplify

Cooking and baking. Recipes often use fractions: 3/4 cup of flour, 1/3 teaspoon of salt. If you need to halve or double a recipe, you are doing fraction arithmetic. Half of 3/4 cup is 3/8 cup.

DIY and measurement. Lumber and hardware come in fractional sizes — 5/8 inch plywood, 3/4 inch pipe. When cutting materials, you need to add and subtract fractions to get the right length. Our length converter handles metric and imperial conversions.

Finance. Interest rates, tax brackets and investment returns all involve fractional percentages. Understanding that 1/4 = 25% or 1/8 = 12.5% helps you quickly estimate costs. Use our discount calculator for sale price calculations.

School and exams. Fractions are a core part of Common Core standards and SAT/ACT math sections. Common exam questions involve adding fractions with different denominators, converting between fractions and decimals, and simplifying. The step-by-step examples above follow the same methods used in standardized test prep.