How to calculate and simplify fractions
For a/b and c/d, addition and subtraction use (ad ± bc)/(bd). Multiplication uses ac/(bd), and division uses ad/(bc), provided the second fraction is not zero. The fraction calculator reduces each result by its greatest common factor and keeps the denominator positive.
Integer arithmetic preserves exact numerators and denominators, including big integer fractions. Each integer input supports up to 100 digits. Decimal conversions accept up to 100 digits total and treat the entered finite decimal as exact.
Mixed numbers and decimal conversions
The mixed number calculator accepts entries such as 2 3/4, -2 3/4, 3/4, or 2. A leading minus applies to the entire mixed number: -2 3/4 equals -11/4. In simplify mode, leave the whole number blank or use 0 when you only have a numerator and denominator. With a nonzero whole part, use a nonnegative numerator and positive denominator.
To convert a decimal to a fraction, remove the decimal point to form the numerator and use a power of ten as the denominator, then reduce. For example, 1.375 = 1375/1000 = 11/8. Results include a reduced fraction, mixed number, decimal, and calculation steps.
Frequently asked questions
How do I add fractions with different denominators?
Cross-multiply to get a common denominator, add the adjusted numerators, and simplify. For example, 1/2 + 1/3 = 5/6.
Can the denominator be zero?
No. A zero denominator is undefined. Dividing by a zero fraction is also rejected.
Does the calculator support negative fractions?
Yes. Put a minus sign on the numerator, denominator, or mixed number. The simplified result places its sign on the numerator.
Why does a decimal result end with an ellipsis?
Decimal results stop after 16 fractional digits. An ellipsis indicates that more digits follow, including repeating decimals. The fraction remains exact.
Input and precision notes
Use plain integers without commas or exponent notation. Decimal-to-fraction mode accepts finite decimals, not repeating-decimal notation. Large fractions remain exact; decimal displays are truncated rather than rounded.
What's changed
- Launched with Fractions, Mixed numbers, Simplify, Decimal to fraction, Fraction to decimal, and Big fractions tabs.