Add, subtract, multiply, or divide fractions and mixed numbers, with the working shown one step at a time — plus quick tools to simplify a fraction or convert to and from decimals.
Leave the whole-number box empty unless you're entering a mixed number.
Reduce any fraction to its lowest terms.
Convert either direction.
Picture a chocolate bar scored into 8 equal squares. If you break off 3 of those squares, you've taken 3/8 of the bar — the bottom number (the denominator) records how many equal pieces the whole bar was cut into, and the top number (the numerator) records how many of those pieces you're talking about. Nothing about a fraction is about "3" or "8" on their own; it's the relationship between them that means something.
A mixed number like 2 3/4 means "two whole bars, plus three quarters of another." An improper fraction says the same thing differently: 11/4, where the numerator is allowed to be bigger than the denominator. Both describe the identical amount — our calculator above lets you type the whole-number part directly instead of forcing you to convert it yourself first, or use a separate tool just for mixed numbers.
Think of denominators as different currencies. You can't add 3 euros and 2 dollars and get a meaningful total until you convert one into the other. Fractions work the same way: 1/3 and 1/4 are sliced differently, so before you can combine them you rescale both to a shared "currency" — the smallest denominator they both divide into evenly. Only once the pieces are the same size can the numerators simply be added or subtracted.
Multiplication skips that step entirely — multiply the numerators, multiply the denominators, done. Division is really multiplication in disguise: dividing by 1/2 asks "how many halves fit into this?", and it turns out that's the same question as multiplying by the flipped fraction, 2/1. That's the entire reason the "flip and multiply" rule works — it isn't an arbitrary trick.
10/20 and 1/2 point to the exact same quantity, but 1/2 is the version everyone recognizes at a glance. Reducing a fraction means dividing the numerator and denominator by the largest number that divides evenly into both, until nothing but 1 divides them both. It doesn't change the value — it just states it in the plainest possible terms.
No. A denominator of zero would mean splitting something into zero pieces, which is undefined — there's no such quantity. Our calculator will flag this rather than guess at an answer.
Exactly like positive ones, except one part of the fraction carries a minus sign. You can put the sign on the whole number, the numerator, or think of it as applying to the fraction as a whole — the calculator normalizes it either way and always returns the denominator as positive.
Only when the denominator's prime factors are limited to 2s and 5s (like 4, 8, 20, 25). Otherwise the decimal repeats forever — 1/3 becomes 0.333..., which we round to a fixed number of places for display rather than showing an infinite string of digits.
Never. Simplifying only rewrites the fraction in smaller numbers — the amount it represents is identical before and after, the same way "one dozen" and "twelve" refer to the same quantity.
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