Fraction Calculator
Add, subtract, multiply, or divide two fractions or mixed numbers. The result includes a simplified fraction, a mixed-number form, and a decimal approximation.
Fraction Calculator tool
About the Fraction Calculator
Students can use the steps to check common-denominator work and reciprocal division. The separate whole-number, numerator, and denominator fields also make it convenient to enter measurements written as mixed numbers.
How Is Fraction Calculated?
Mixed numbers are converted to improper fractions before applying the operation. The greatest common divisor reduces the result to lowest terms.
A denominator must be positive and nonzero. To enter a negative mixed number, put the sign on the whole part; for a negative proper fraction, put it on the numerator.
a/b + c/d = (ad + bc)/(bd)
a/b − c/d = (ad − bc)/(bd)
a/b × c/d = ac/(bd)
a/b ÷ c/d = ad/(bc), c ≠ 0
Example
1 1/2 + 3/4 = 3/2 + 3/4 = 18/8 = 9/4 = 2 1/4.
How to Use the Fraction Calculator
- Enter the first whole part, numerator, and positive denominator.
- Enter the second fraction in the same format.
- Select addition, subtraction, multiplication, or division.
- Read the reduced fraction, mixed number, and decimal.
- Review the improper-fraction conversion and simplification steps.
Fraction Calculator Examples
Add unlike denominators
1/2 + 1/3 = 5/6.
Divide fractions
3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8 = 1 7/8.
Subtract mixed numbers
2 1/4 − 1 1/2 = 9/4 − 6/4 = 3/4.
Exact and approximate forms
The simplified numerator and denominator represent the exact rational result within the supported integer range. The decimal display can be rounded, especially for repeating decimals.
Dividing by a fraction
Division uses the reciprocal of the second fraction. A zero numerator in that second fraction makes division undefined.
Frequently Asked Questions
What is a mixed number?
It combines a whole number and a proper fraction, such as 2 1/3.
Why can a denominator not be zero?
A fraction represents division; division by zero has no defined real-number value.
How is a fraction simplified?
Divide the numerator and denominator by their greatest common divisor.
How do I enter −1 1/2?
Enter −1 as the whole part, 1 as the numerator, and 2 as the denominator.
Why is a very large fraction rejected?
The calculator rejects operations beyond JavaScript safe-integer precision instead of displaying an apparently exact but unreliable fraction.