Add, subtract, multiply or divide fractions — or simplify one — with exact reduced answers in mixed, decimal and percent forms, plus every step.
All fraction arithmetic happens locally in your browser. Nothing ever leaves your device.
The history lives only in this page — reloading clears it.
Every operation is done in exact fraction arithmetic — no floats are used until the final decimal display — so 1/3 + 1/6 returns 1/2, never 0.49999999. The calculator keeps numerators and denominators as integers, applies the operation, then reduces the answer once with the greatest common divisor. Addition and subtraction first build a common denominator; multiplication and division cancel factors before they ever let numbers grow large.
By the usual sign rules. A minus in front of a fraction applies to the whole value, so it is stored on the numerator; a negative denominator is folded onto the numerator too, because -a/-b = a/b and -a/b = a/-b. Multiplying or dividing two negatives gives a positive, and adding negatives works like walking further left on the number line. You can type the minus sign in any of the four boxes.
Multiply the whole part by the denominator, add the numerator, and keep the same denominator: 3 1/4 becomes (3 × 4 + 1)/4 = 13/4. The calculator does the reverse automatically — whenever a result is improper it also prints the mixed-number form — and the Steps panel shows the division line behind it.
A fraction has an exact terminating decimal only when its reduced denominator is built from 2s and 5s (halves, quarters, fifths, eighths, twentieths...). Denominators like 3, 6, 7, 9, 11 produce repeating decimals, so 1/3 is shown as ≈ 0.3333333333 — ten decimal places, rounded. The fraction result stays exact; that is the point of keeping the numerator/denominator form on screen.
Because division asks 'how many of these fit in that', and multiplying by the reciprocal answers exactly that: a ÷ (b/c) = a × (c/b), since (b/c) × (c/b) = 1 — the flipped fraction is the multiplicative inverse. The Steps panel shows this keep-change-flip line before doing the multiplication so the flip never feels like a magic rule.
No. All numerator and denominator arithmetic runs in your browser with plain JavaScript, and the calculation history lives only in memory until you reload the page. Nothing is stored on a server, and there is no account or network request attached to a computation.
If you just finished with Fraction Calculator, the natural next steps are Exponent Calculator, Prime Factorization Calculator, LCM & HCF Calculator, or browse every tool in Daily Tools.