Fraction Calculator – Add, Subtract, Multiply & Divide Fractions

Fraction Calculator
RESULT:

Share this calculator

How can this calculator be improved?

Do fractions make you crazy? Our fraction calculator can be useful whether you're completing homework, getting ready for a test, or simply need fast results. Choose your operation (addition, subtraction, multiplication, or division), enter any proper or improper fraction, and receive immediate results along with thorough, step-by-step explanations. It's like having a free, round-the-clock math instructor!

A quick look at fraction arithmetic rules:

  • Subtraction and Addition: The least common denominator (LCM) should always be found: (a·d ± b·c) / (b·d) = a/b ± c/d
  • Multiplication: Numerator × Numerator and Denominator × Denominator: (a/b) × (c/d) = (a·c) / (b·d)
  • Division: Multiply the first fraction by the second fraction's reciprocal: (a/b) ÷ (c/d) = (a·d) / (b·c)
  • Simplifying: To simplify, divide the denominator and numerator by the greatest common divisor (GCD).

A fraction: what is it?

In mathematics, a fraction can be used to express a portion of a whole, a quantity, or a ratio between two integers. With this math tool, you may enter improper or simple fractions, choose your mathematical operator, and get a simplified response or a reduced mixed number right away. By handling the challenging computations and clearly displaying the mathematical procedure, it makes it simple to understand how the outcome was obtained.

Note: You are dealing with a mixed number and should utilize the mixed number calculator instead if your math problem includes a whole number before the fraction.

Additionally, remember that multiplication is all that is needed for word problems asking for a fraction "of" a number (e.g., "what is 3/4 of 5/9?").

How to Utilize This Tool

Step 1: Enter your first fraction
In the input areas for the first fraction, enter the numerator (top number) and denominator (bottom number).

Step 2: Choose your operation
Choose the calculation you want to make: addition (+), subtraction (−), multiplication (×), or division (÷).

Step 3: Enter your second fraction
In the same manner, enter the second fraction's numerator and denominator.

Step 4: Click Calculate
The tool solves the equation right away and shows your result—which is simplified completely and transformed to a mixed number if the response is an improper fraction.

Step 5: Review the step-by-step breakdown
The tool displays precisely how it arrived at your result below it: by finding a common denominator (for addition/subtraction), multiplying directly (for multiplication), or using "keep, change, flip" (for division)—enabling you to trace or double-check the arithmetic yourself.

A note regarding accuracy: All calculations are carried out instantly in your browser; nothing you enter is stored or transmitted. Every result is calculated using exact fraction arithmetic and automatically simplified using the greatest common divisor—never rounded or approximated.

Examples

Examples for Addition

Example 1: What is 2/5 + 1/3?

25 + 13 = 2×3 + 5×15×3 = 6 + 515 = 1115

Example 2: What is 3/4 + 2/8?

34 + 28 = 3×8 + 4×24×8 = 24 + 832 = 3232 = 1

Examples for Subtraction

Example 1: What is 5/6 − 1/4?

56 − 14 = 5×4 − 6×16×4 = 20 − 624 = 1424 = 712

Example 2: What is 7/8 − 1/3?

78 − 13 = 7×3 − 8×18×3 = 21 − 824 = 1324

Examples for Multiplication

Example 1: What is 3/5 × 2/7?

35 × 27 = 3×25×7 = 635

Example 2: What is 2/3 × 3/4?

23 × 34 = 2×33×4 = 612 = 12

Examples for Division

Example 1: What is 5/8 ÷ 1/4?

58 ÷ 14 = 5×48×1 = 208 = 2 12

Example 2: What is 3/4 ÷ 2/5?

34 ÷ 25 = 3×54×2 = 158 = 1 78

Fraction Rules & Concepts

Understanding fractions in everyday life

Thinking of fractions as pieces of a whole is the easiest approach to understand them. For instance, you have eaten 9/24 of the box if you have 24 donuts and your family consumes 9 of them.

Fractions also work well for representing values that fall between two whole numbers. The distance to your gym is more than 5 kilometers but less than 6 if it is 5.4 kilometers away. That extra 0.4 is a fraction of a kilometer. This distance can be expressed as "5 and 4 tenths" kilometers.

Rules for calculating with negative fractions

When solving equations with negative fractions, simply attach the minus sign directly to the top number (numerator). If your fraction is -5/7, enter -5 as the numerator and 7 as the denominator.

  • If only the top or only the bottom number has a minus sign, the entire fraction becomes negative.
  • If both the top and bottom numbers have a minus sign, they cancel each other out, resulting in a positive fraction.
  • Just like in normal arithmetic, the same sign always leads to a positive result, while opposite signs always give a negative result.

How to add or subtract fractions with different denominators

Before adding or subtracting fractions, always examine your denominators (the bottom numbers). You must find the least common denominator (LCD) if these denominators do not match. Finding this shared base is made extremely simple by using an online common denominator calculator.

Once you have found the common base:

  1. Determine the number you need to multiply the original denominator by to reach it.
  2. Multiply the numerator (the top number) by that same value.
  3. Repeat this for every fraction in your equation.
  4. Now simply add or subtract the numerators while keeping the denominator unchanged.
  5. Finally, simplify your final result and convert any improper fractions to mixed numbers.

Simple rules for multiplying and dividing fractions

Multiplication: Simply multiply all numerators together and do the same for the denominators. Simplify the result at the end.

Division: Use the "keep, change, flip" trick (reciprocal):

  • Keep: Leave the first fraction exactly as it is.
  • Change: Change the division symbol (÷) to the multiplication symbol (×).
  • Flip: Flip the second fraction completely (find its reciprocal).

Then simply multiply directly and simplify the result.

Fraction formulas with cross-multiplication

By utilizing cross-multiplication formulas, you can completely avoid having to find the common denominator. When solving fractional equations by hand, this is frequently a considerably faster method.

Addition

Formula

ab + cd = ad + bcbd

Example

47 + 13 = 1921
Subtraction

Formula

ab − cd = ad − bcbd

Example

47 − 13 = 521
Multiplication

Formula

ab × cd = acbd

Example

47 × 13 = 421
Division

Formula

ab ÷ cd = adbc

Example

47 ÷ 13 = 127

Frequently Asked Questions (FAQ)

What if my denominators are different – do I have to find a common denominator myself?

No. The calculator finds the common denominator automatically and shows you the entire step-by-step process so you can see exactly how it got there.

Does the calculator simplify (reduce) the final result?

Yes – every result is automatically reduced to its simplest form. If the answer is an improper fraction, it is also converted into a mixed number.

Can I use this tool for mixed numbers like 2 ¾?

Not directly – this calculator is designed for proper and improper fractions. For a whole number combined with a fraction, use the mixed number calculator instead.

How do I enter a negative fraction?

Add the minus sign to the numerator. For -5/7, enter -5 as the numerator and 7 as the denominator. If both the numerator and denominator are negative, they cancel each other out and the result is positive.

What does "keep, change, flip" mean in division?

This is the method used for dividing fractions: keep the first fraction as it is, change the ÷ to ×, and flip the second fraction (find the reciprocal). Then multiply directly.

How do I calculate a fraction "of" a number, like "What is 3/4 of 5/9"?

"Of" means to multiply. Enter 3/4 and 5/9 and select the multiplication operation.

Why is my answer as an improper fraction shown as a mixed number?

If the numerator of a fraction is larger than its denominator (like an improper result), the calculator automatically converts it to a mixed number, as this is usually the more useful way to read the answer.

Can I calculate more than two fractions at once?

No – the calculator works with two fractions per calculation. For a longer equation, calculate two fractions at a time and then use that result as one of the fractions in your next calculation.

Do I have to cross-multiply, or does the calculator use common denominators?

The calculator finds the actual least common denominator for addition and subtraction (the standard classroom method), rather than just cross-multiplying. Cross-multiplication is shown separately as a faster manual shortcut if you are solving the problem by hand.

Related Calculators

Last updated: July 30, 2026

↑ Nach oben