Fraction Calculator
Add, subtract, multiply and divide fractions — simplified automatically, with the mixed number and decimal shown.
About this tool
Fractions resist mental arithmetic because each operation has its own rule: addition and subtraction need a common denominator, multiplication goes straight across, and division flips the second fraction. This calculator applies the right rule, then simplifies the answer by the greatest common divisor and shows it as a simplified fraction, as a mixed number when it exceeds 1 (with the plain fraction alongside), and as a decimal — marked ≈ when the decimal is rounded, because 0.3333 is not exactly 1/3. Decimal entries are converted to fractions first, so 1.5 over 2 works out as 3/4.
It is built for the places fractions actually appear: recipes (halving 3/4 of a cup), woodworking and measurements, homework, and probability. To enter a mixed number like 1 1/2, add the whole part into the numerator first — enter it as 3/2. Negative fractions are handled with the sign carried on the numerator, as convention requires.
How to use it
- Enter the first fraction's numerator and denominator.
- Choose the operation.
- Enter the second fraction — the simplified answer, mixed number and decimal appear instantly.
Frequently asked questions
How do you add fractions with different denominators?
Rewrite both over a common denominator (the product of the two always works), add the numerators, then simplify: 1/2 + 1/3 = 3/6 + 2/6 = 5/6.
How do you divide fractions?
Keep the first, flip the second, multiply: 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8 = 1 7/8.
What does “simplify” mean?
Dividing numerator and denominator by their greatest common divisor so the fraction is in lowest terms: 6/8 becomes 3/4. This calculator always simplifies.