How it works
How to use this fraction calculator
- Choose add, subtract, multiply, or divide.
- Enter each side as a mixed number if needed: whole, numerator, and a non-zero denominator. Leave whole blank for a proper fraction.
- Read the reduced fraction, the mixed-number form, and a decimal check.
Formula
The calculation formula
a/b + c/d = (ad + bc) / bd01
Convert each mixed number to an improper fraction.
02
Apply the selected operation using a common denominator or cross-multiplying.
03
Divide numerator and denominator by their greatest common divisor.
Worked examples
Example calculations
Unlike denominators
1/2 + 1/3 = 3/6 + 2/6 = 5/6.
Mixed number times a fraction
1 1/2 × 2/3 = 3/2 × 2/3 = 1.
When to use it
Common use cases
- Add unit fractions such as 1/2 + 1/3
- Multiply mixed numbers
- See the reduced fraction, mixed form, and decimal together
Limits
Assumptions and limits
- Whole parts and numerators must be integers. Denominators must be non-zero integers.
- An empty whole or numerator is treated as 0.
- Division by a zero fraction is rejected.
Questions
Frequently asked questions
How do you add fractions with different denominators?
Cross-scale to a common denominator: a/b + c/d = (ad + bc) / bd, then simplify.
What is a mixed number in this calculator?
A whole part plus a proper fraction, such as 1 1/2. It is converted to 3/2 before the operation.
Sources
Sources and review
- Wikipedia — Fraction (mathematics)
Four operations on rational numbers and reduction by gcd
Accessed August 25, 2026