Fractions Calculator

Run any of the four basic fraction operations from one calculator instead of bookmarking four separate pages.

How to Use the Fractions Calculator

Pick Add, Subtract, Multiply, or Divide from the toggle, then enter two fractions — switching operations keeps both fractions in place, so it's easy to compare all four results for the same pair of numbers.

This is the combined version of the site's four separate fraction-operation calculators — Adding, Subtracting, Multiplying, and Dividing Fractions — built for anyone who doesn't want four different bookmarks for what is, underneath, the same pair of number fields with a different operator applied.

Add:      a/b + c/d = (ad + bc) / bd
Subtract: a/b − c/d = (ad − bc) / bd
Multiply: a/b × c/d = (a × c) / (b × d)
Divide:   a/b ÷ c/d = (a × d) / (b × c)

One of these four operations is not like the others. Addition and subtraction can't touch the numerators until both fractions share the same denominator, which is what the cross-multiplication in the first two lines is actually doing. Multiplication and division skip that step entirely — no shared "size of piece" to establish first, just numerator-times-numerator and denominator-times-denominator, or the flipped version for division.

That's the real reason fraction addition feels harder than fraction multiplication to most people first learning it, even though multiplication is usually introduced later. It isn't more advanced math — it's one extra setup step multiplication and division never needed.

Order matters for subtraction and division but not for addition or multiplication — swap the two fractions before subtracting or dividing and the answer changes, sometimes flipping sign entirely. Every result comes back reduced to lowest terms, using the fractions' greatest common factor, with the decimal equivalent shown alongside.