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Fraction Calculator: Add, Subtract, Multiply & Divide

Fraction calculator online: add, subtract, multiply, and divide fractions with automatic simplification and decimal equivalents.

Updated 2026-08-16

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Features

  • Add two fractions with different denominators
  • Subtract fractions with automatic common denominator
  • Multiply fractions directly
  • Divide fractions by inverting and multiplying
  • Simplify fractions to lowest terms
  • Show decimal equivalent
  • Instant calculation as you type
  • Perfect for math homework and cooking
  • Handles improper fractions

How to Use

  1. 1Enter the first fraction (numerator and denominator).
  2. 2Select the operation (add, subtract, multiply, divide, or simplify).
  3. 3Enter the second fraction if needed.
  4. 4View the result as a fraction and decimal.
  5. 5See the simplified form automatically.
  6. 6Adjust a recipe by scaling fractions: multiply 3/4 cup by 2 to get 1 1/2 cups, directly in the calculator.
  7. 7Compare two fractions to see which is larger: subtract one from the other and check if the result is positive or negative.
  8. 8Simplify a fraction you encounter in carpentry or woodworking: enter 24/32 and instantly get the simplified 3/4.
  9. 9Convert an improper fraction like 7/4 to its decimal equivalent 1.75 for use in a spreadsheet or financial calculation.
  10. 10Add up measurements from a tape measure: enter 1/2 + 1/4 + 1/8 to get 7/8 inch for precise woodworking cuts.

Frequently Asked Questions

How do I add fractions with different denominators?

Find a common denominator (usually the LCM), convert each fraction, then add numerators. For 1/2 + 1/3: common denominator is 6, so 3/6 + 2/6 = 5/6. The calculator does this automatically.

How do I multiply fractions?

Multiply numerators together and denominators together. For 2/3 × 3/4: (2×3)/(3×4) = 6/12 = 1/2. Always simplify the result.

How do I divide fractions?

Multiply by the reciprocal (flip the second fraction). For 1/2 ÷ 1/4: 1/2 × 4/1 = 4/2 = 2. The calculator handles this automatically.

What does simplifying a fraction mean?

Simplifying means reducing to lowest terms by dividing both numerator and denominator by their greatest common divisor (GCD). For 12/16, GCD is 4, so 12÷4 / 16÷4 = 3/4. Simplified fractions are easier to work with and are the standard way to present results.

Can I use improper fractions?

Yes. Improper fractions (numerator > denominator) work fine. For example, 7/4 = 1.75. The calculator doesn't convert to mixed numbers, but you can see the decimal equivalent.

Can I calculate with three or more fractions at once?

Each operation takes two fractions, so for three fractions you chain the results: 1/2 + 1/3 + 1/6 → 1/2 + 1/3 = 5/6, then 5/6 + 1/6 = 1. The decimal view helps you keep track between steps. Multiplication and division chain the same way.

Can I enter mixed numbers or whole numbers?

Whole numbers work by entering them as a fraction: 3 becomes 3/1. Mixed numbers like 1 1/2 are not directly supported: convert to an improper fraction first by multiplying the whole part by the denominator and adding the numerator (1 1/2 → 3/2), then enter that.

How do I find the least common denominator (LCD)?

The LCD is the least common multiple (LCM) of the denominators. For 1/3 + 1/5: LCM(3,5) = 15. Convert: 5/15 + 3/15 = 8/15. The calculator finds the LCD automatically for any pair of fractions.

How do I convert an improper fraction to a mixed number?

Divide numerator by denominator. For 7/4: 7 ÷ 4 = 1 remainder 3, so 1 3/4. The calculator shows the decimal equivalent (1.75) which represents the same value as the mixed number. For exact mixed number display, use a dedicated fraction-to-mixed-number tool.

How do I compare two fractions?

Cross-multiply: for a/b and c/d, compare a×d vs b×c. If a×d > b×c, then a/b > c/d. For 3/4 vs 2/3: 3×3=9, 4×2=8, 9>8 so 3/4 > 2/3. The calculator can do this by subtracting one fraction from another.

What is a complex fraction?

A complex fraction has a fraction in the numerator, denominator, or both. For example, (1/2)/(3/4). To simplify: multiply numerator by reciprocal of denominator: 1/2 × 4/3 = 4/6 = 2/3. The calculator handles this by performing the division operation.

Can fractions be used in real-world measurements?

Yes. Fractions are essential in: cooking (3/4 cup, 1/2 teaspoon), carpentry (3/8 inch, 1/4 inch), sewing (5/8 yard), construction (2/3 of a wall), medicine (1/2 tablet), and finance (1/4 of annual interest). The calculator handles all these real-world scenarios.

Why does my result look different from what I calculated by hand?

The calculator always reduces results to the simplest form: 4/8 becomes 1/2, and 10/4 becomes 5/2. If your handwritten result is unreduced or left as an improper fraction, it looks different but represents the same value. Negative results are normalized to the numerator (for example, -2/3, not 2/-3). Check the simplified output; the math is equivalent.

Can I calculate a fraction raised to a power, like (2/3)²?

Not directly: this calculator does the four basic operations plus simplification, with no exponent button. But a power of a fraction is easy by hand: (a/b)ⁿ = aⁿ/bⁿ. For (2/3)², compute 2² = 4 and 3² = 9, then enter 4/9 here, or enter 2/3 and read the decimal (0.6667), then raise that if your use case tolerates rounding.

What happens if I enter zero as a denominator?

The calculator rejects it: division by zero is undefined, and no fraction may have a denominator of zero, so an input like 5/0 or 0/0 produces no valid result. Double-check inputs that come from word problems or calculator transcriptions. A numerator of zero (0/5) is perfectly valid and simplifies to 0, and negative signs belong in the numerator; the tool normalizes them there automatically.

I accidentally entered the numerator and denominator swapped: how do I notice?

Swap errors are easy to spot with the decimal view: 3/4 entered as 4/3 shows 1.3333 instead of 0.75, and for division the result is the reciprocal: 1/2 ÷ 3/4 entered swapped gives 1.5 instead of 2/3. When an answer looks off by more than an order of magnitude, re-check the input order. If you only need the result and not the intermediate steps, the decimal column is the fastest sanity check.

Can I enter a decimal like 0.5 instead of a fraction?

No, both fields take whole numbers only, a numerator and a denominator (e.g., 1/2, not 0.5). Convert first: 0.5 = 5/10 = 1/2, and 0.75 = 3/4. For a decimal you cannot easily convert, read the result column instead: every fraction result already shows its decimal equivalent, so enter the fraction form and take the decimal from the output.