Add unlike fractions
3/4 + 2/3 = (3 × 3 + 2 × 4) / 12 = 17/12, which is also 1 5/12.
Add, subtract, multiply, and divide
Fraction calculator
Calculate with two fractions, reduce the result, and follow the operation one step at a time.
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Formula and steps included
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Formula
How fraction operations work
Add or subtract: a/b ± c/d = (ad ± bc) / bd; Multiply: a/b × c/d = ac / bd; Divide: a/b ÷ c/d = ad / bc
Addition and subtraction need a common denominator because the parts must have the same size. Cross-multiplying creates an equivalent common-denominator form.
Multiplication works straight across. Division uses the reciprocal of the second fraction, and every final fraction can be reduced by dividing its numerator and denominator by their greatest common factor.
How to use the formula
Choose the operation
Select addition, subtraction, multiplication, or division before entering the two fractions.
Check both denominators
A denominator cannot be zero because division by zero is undefined.
Apply the matching formula
Build a common denominator for addition or subtraction, multiply straight across, or invert the second fraction before division.
Simplify the result
Divide the numerator and denominator by their greatest common factor and convert to a mixed number if that format is useful.
Worked examples
Fraction calculator examples
Divide and simplify
5/6 ÷ 10/9 = 5/6 × 9/10 = 45/60 = 3/4.
Common questions
Fraction calculator FAQ
Can the fraction calculator handle improper fractions?
Yes. An improper fraction is calculated the same way as any other fraction, and the simplified result can also be expressed as a mixed number.
Why can a denominator not be zero?
A fraction represents division by its denominator. Division by zero has no defined numeric result, so every denominator must be nonzero.
How is a fraction simplified?
Find the greatest common factor of the numerator and denominator, then divide both by that factor. Their ratio stays the same.
Are my fractions sent anywhere?
Your fractions are not saved by default or uploaded. You can opt into Remember on this device or download a local JSON backup.