Skip to content
SacaCuenta

Fraction Calculator

Add, subtract, multiply and divide fractions, or reduce a single fraction, and get the answer in simplest form, as a mixed number and as a decimal, with every step shown.

FreeNo sign-upInstant resultsUpdated:

Calculator

What do you want to do?

Simplified result

5/6

1/2 + 1/3

Mixed number

—

Not an improper fraction

Decimal (approx.)

0.833333

Step by step

Common denominator (LCM of 2 and 3): 6

1/2 = 3/6 and 1/3 = 2/6

3 + 2 = 5 → 5/6

Keep analyzing

For estimates only. Double-check the numbers before making important decisions.

How to use the calculator

  • Operate on two fractions: enter the numerator (top number) and denominator (bottom number) of each fraction and pick +, −, × or ÷.
  • Simplify a fraction: enter one fraction to reduce it to simplest form.
  • Negative fractions: put a minus sign on the numerator or the denominator. The result always shows the sign on the numerator.
  • Mixed numbers: convert them to improper fractions first. For example, 2 1/3 becomes 7/3.

Rules for fraction operations

a/b + c/d = (a × d + c × b) / (b × d)
a/b × c/d = (a × c) / (b × d)
a/b ÷ c/d = a/b × d/c
The calculator adds and subtracts using the least common denominator (the LCM of the denominators).

To divide, keep the first fraction, change ÷ to ×, and flip the second fraction (use its reciprocal): 3/4 ÷ 1/2 = 3/4 × 2/1 = 6/4 = 3/2.

Reducing to simplest form

A fraction is in simplest form when the numerator and denominator have no common factor other than 1. To get there, divide both by their greatest common factor (GCF): 18/24 → 3/4, because the GCF of 18 and 24 is 6.

How to read the result

  • Simplified result: the answer in simplest form. If the numerator is larger than the denominator, it's an improper fraction (7/4).
  • Mixed number: the same amount written as a whole number plus a proper fraction (1 3/4).
  • Decimal: the value rounded to 6 decimal places (1.75).

A denominator can never be 0, and you can't divide by a fraction that equals 0.

Example

1/2 + 1/3 = 5/6: the least common denominator is 6, so 1/2 becomes 3/6 and 1/3 becomes 2/6. And 2/3 × 9/4 = 3/2, which is 1 1/2 as a mixed number and 1.5 as a decimal.

  1. LCM(2, 3) = 6
  2. 1/2 = 3/6 and 1/3 = 2/6
  3. 3/6 + 2/6 = 5/6
  4. (2 × 9) / (3 × 4) = 18/12
  5. Divide both by the GCF, 6: 18/12 = 3/2 = 1 1/2

Common mistakes

  • Adding the numerators and the denominators straight across: 1/2 + 1/3 is 5/6, not 2/5.
  • Forgetting to flip the second fraction when dividing.
  • Typing a mixed number like 2 1/3 as 21/3: convert it to the improper fraction 7/3 first.

Frequently asked questions

How do you add fractions with different denominators?

Find a common denominator (the LCM of the denominators), rewrite each fraction with that denominator, then add the numerators. For 5/6 − 1/4, the LCD is 12: 10/12 − 3/12 = 7/12.

How do you turn an improper fraction into a mixed number?

Divide the numerator by the denominator. The quotient is the whole number and the remainder is the new numerator: 7 ÷ 4 = 1 remainder 3, so 7/4 = 1 3/4.

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

Multiply the whole number by the denominator and add the numerator, keeping the same denominator: 2 1/3 = (2 × 3 + 1)/3 = 7/3.

How do you convert a fraction to a decimal?

Divide the numerator by the denominator. 3/8 = 3 ÷ 8 = 0.375. The calculator shows the decimal next to every result.

Related calculators

Keep going with the next step.