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Fraction Calculator
Add, subtract, multiply or divide two fractions, simplify a fraction to lowest terms, or turn a decimal into a fraction — exact answers, with the working shown so you can check every step.
Add, subtract, multiply or divide two fractions
Simplify a fraction
Decimal to fraction
Results are exact fractions. Decimals are shown rounded to 6 places. The decimal-to-fraction result is the closest fraction with a denominator up to 1,000.
How it works
Adding/subtracting: convert to a common denominator, then add or subtract the numerators: a/b ± c/d = (a·d ± c·b)/(b·d), then simplify. Multiplying: multiply tops and bottoms: (a/b)×(c/d) = (a·c)/(b·d). Dividing: flip the second fraction and multiply: (a/b)÷(c/d) = (a·d)/(b·c). Simplifying: divide top and bottom by their greatest common divisor (GCD). Worked examples: 3/4 + 2/3 = 9/12 + 8/12 = 17/12 = 1 5/12 ≈ 1.416667. 24/36 simplifies by GCD 12 to 2/3. 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8 = 1 7/8. 0.75 = 3/4.
Frequently asked questions
How do I simplify a fraction?
Divide the numerator and denominator by their greatest common divisor — the largest number that divides both. 24/36: the GCD is 12, so 24÷12 / 36÷12 = 2/3.
How do I add fractions with different denominators?
Give them a common denominator first: multiply each fraction top and bottom so both bottoms match, then add the tops. 3/4 + 2/3 becomes 9/12 + 8/12 = 17/12.
What is the difference between an improper fraction and a mixed number?
An improper fraction has a numerator larger than its denominator (17/12). A mixed number splits it into a whole part plus a proper fraction (1 5/12). They are the same value.
Why do you flip the second fraction when dividing?
Dividing by a fraction is the same as multiplying by its reciprocal — the flipped version. 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8.
Can every decimal be written as an exact fraction?
Terminating decimals can (0.75 = 3/4). Repeating decimals are approximated here to the closest fraction with a denominator up to 1,000 — 0.3333333333 gives 1/3, accurate to about one part in a billion.