Fraction Calculator
Add, subtract, multiply or divide two fractions. Get the answer in lowest terms, as a mixed number and as a decimal, with every step shown.
Add, subtract, multiply or divide two fractions and get the answer in lowest terms, as a mixed number and as a decimal. The working is listed step by step — the common denominator for adding and subtracting, multiplying straight across, and flipping the second fraction to divide — so you can follow the method or check homework.
How to use this tool
- Enter the numerator (top) and denominator (bottom) of the first fraction.
- Choose add, subtract, multiply or divide.
- Enter the second fraction. A whole number such as 3 is 3 over 1; put a minus sign on the numerator for a negative fraction.
- Read the simplified result, the mixed number and the decimal, with the steps underneath.
Formula
a/b ± c/d = (a·L/b ± c·L/d) / L a/b × c/d = ac / bd a/b ÷ c/d = ad / bc
L is the least common denominator, the lowest common multiple of b and d. Every answer is reduced by dividing the numerator and denominator by their greatest common divisor (GCD).
Example
3/4 + 1/6: the least common denominator of 4 and 6 is 12, so 3/4 = 9/12 and 1/6 = 2/12. Adding the numerators gives 11/12, already in lowest terms because 11 and 12 share no factor. As a decimal that is 0.9166666667 — exactly 0.91(6), with the 6 repeating forever.
Frequently asked questions
How do I simplify a fraction?
Divide the numerator and the denominator by their greatest common divisor. For 18/24 the GCD is 6, which gives 3/4. The calculator does this to every answer and shows the factor it used.
Why does dividing flip the second fraction?
Dividing by c/d asks how many c/d fit into the first number, which is the same as multiplying by the reciprocal d/c. So 3/4 ÷ 1/2 = 3/4 × 2/1 = 6/4 = 3/2.
Can I enter mixed numbers?
Convert them first: 2 1/3 becomes (2 × 3 + 1)/3 = 7/3. Or use the mixed number calculator, which has a separate box for the whole part.
What do the brackets in the decimal mean?
They mark the repeating block: 0.(3) means 0.333… and 0.1(6) means 0.1666…. Fractions whose reduced denominator has only 2s and 5s as prime factors give terminating decimals instead.
Last updated: 2026-10-30