Math Calculators / Free Tools
Free Fraction Calculator
Use these free fraction calculators to add, subtract, multiply, and divide fractions and mixed numbers, simplify fractions to their lowest terms, and convert between fractions and decimals - including a version built for very large numbers. No sign-up required.
Fraction Calculator
Add, subtract, multiply, or divide two fractions.
Mixed Numbers Calculator
Add, subtract, multiply, or divide mixed numbers, e.g. -2 3/4.
Simplify Fractions Calculator
Reduce a fraction to its lowest terms.
Decimal to Fraction Calculator
Convert a decimal number into a simplified fraction.
Fraction to Decimal Calculator
Convert a fraction into its decimal equivalent.
Big Number Fraction Calculator
For fractions with very large integer numerators or denominators.
What is a fraction and how these calculators work
A fraction represents part of a whole, written as a numerator (the top number) over a denominator (the bottom number). If you split a pizza into 8 equal slices and eat 3 of them, you've eaten 3/8 of the pizza - 3 is the numerator, 8 is the denominator. A fraction's denominator can never be zero, since dividing by zero is undefined.
These calculators handle the standard operations performed on fractions - addition, subtraction, multiplication, division, simplification, and conversion to and from decimals - and automatically reduce every result to its simplest form.
Addition and subtraction
Adding or subtracting fractions requires a common denominator first, since you can only combine parts that are measured in the same-sized pieces. The standard approach multiplies each fraction's numerator and denominator by the other fraction's denominator, giving both fractions the same denominator before combining the numerators.
Multiplication
Multiplying fractions is more direct - no common denominator is needed. Multiply the numerators together, multiply the denominators together, then simplify the result.
Division
Dividing by a fraction is the same as multiplying by its reciprocal (flip the numerator and denominator of the fraction you're dividing by, then multiply).
Simplifying fractions
A fraction is in its simplest form when the numerator and denominator share no common factor other than 1. To simplify, divide both the numerator and denominator by their greatest common factor (GCF).
Converting between fractions and decimals
To convert a decimal to a fraction, use each digit after the decimal point as part of a fraction over a power of 10, then simplify. To convert a fraction to a decimal, simply divide the numerator by the denominator - some fractions convert to a terminating decimal, while others repeat indefinitely.
Example: 2/7 = 0.285714... (repeating)
Common searches these calculators answer
- How do I add or subtract fractions with different denominators?
- How do I simplify a fraction to its lowest terms?
- How do I convert a decimal to a fraction?
- How do I convert a fraction to a decimal?
- How do I add or subtract mixed numbers?
- How do I work with fractions that have very large numbers?
How to use these calculators
- Fraction Calculator: enter both fractions' numerators and denominators, choose an operation, and click Calculate.
- Mixed Numbers Calculator: enter two mixed numbers (e.g. "-2 3/4"), choose an operation, and click Calculate.
- Simplify Fractions Calculator: enter a numerator and denominator and click Calculate to reduce it to lowest terms.
- Decimal to Fraction Calculator: enter a decimal number and click Calculate to see it as a simplified fraction.
- Fraction to Decimal Calculator: enter a numerator and denominator and click Calculate to see the decimal value.
- Big Number Fraction Calculator: enter very large whole-number numerators and denominators as text and click Calculate for an exact result.
Tips
- Every result is automatically reduced to its simplest form - if you were expecting an unsimplified answer for homework, remember to check your teacher's requirements on showing intermediate steps.
- For repeating decimals, the Fraction to Decimal calculator shows a rounded value rather than the infinite repeating digits - the repeating pattern itself is noted where relevant.
- Negative mixed numbers should have the minus sign before the whole number, like "-2 3/4", which applies to the whole value.
- Use the Big Number calculator only when your numbers exceed about 15 digits - for anything smaller, the regular Fraction Calculator is simpler and works identically.
Frequently asked questions
Are these fraction calculators free to use?
Yes. They are completely free, work in your browser, and do not require any sign-up or download.
Why is my answer shown as a fraction instead of a decimal?
Fractions are kept in exact fraction form because converting to a decimal can lose precision for repeating decimals. Each result also shows the decimal equivalent alongside the fraction so you have both.
What does it mean to simplify a fraction?
Simplifying means reducing a fraction so the numerator and denominator have no common factor left other than 1, which makes the fraction easier to read and work with without changing its value.
Can I enter negative fractions?
Yes. Enter a negative sign on the numerator for a basic fraction, or before the whole number for a mixed number (e.g. "-2 3/4").
When would I need the Big Number Fraction Calculator?
Regular calculators, including this one's standard fraction calculator, lose precision on whole numbers larger than about 15-16 digits due to how computers store numbers. The Big Number calculator is built specifically to handle those very large numerators and denominators exactly.
