A fraction calculator adds, subtracts, multiplies, or divides two fractions and keeps the answer as a fraction. 1/2 + 1/3 is 5/6, not 0.8333 with a hopeful number of decimals. This page computes the unsimplified result, the reduced fraction, and a decimal equivalent for convenience. The decimal is a view. The fraction is the result.
Each side has a numerator and a denominator. Denominators cannot be 0. Division by a zero fraction is rejected. Inputs must be whole numbers, not 1.5 in the numerator. If you need decimals in a ratio, the Ratio Calculator scales them. The same gcd used to reduce 12/18 is available on its own in the GCD & LCM Calculator.
Work runs in the browser with integer arithmetic inside JavaScript’s safe integer range. Products that overflow that range are refused instead of silently rounded. That is stricter than a pocket calculator that would give you a float and call it a fraction.
The three result rows stay hidden until the inputs are valid. A previous 5/6 will not sit next to an error about a zero denominator.
Add: (n1/d1) + (n2/d2) = (n1×d2 + n2×d1) / (d1×d2). Subtract uses a minus in the numerator. Multiply: (n1×n2)/(d1×d2). Divide: (n1×d2)/(d1×n2), and n2 must not be 0. Simplify by dividing numerator and denominator by their gcd, then move a negative sign to the numerator.
1/2 + 1/3 → unsimplified 5/6, simplified 5/6, decimal 0.833… (trimmed). 2/4 + 2/4 → unsimplified 16/16, simplified 1, decimal 1. 1/2 ÷ 0/3 is rejected because the second fraction is zero. 1/0 is rejected as an input.
1/2 + 1/3 = 5/6
2/4 + 2/4 = 16/16 = 1Complex fractions, such as (1/2)/(3/4), are just division of two fractions: 1/2 ÷ 3/4. Mixed numbers are not parsed: type 3/2 rather than 1 1/2. If you convert 1 1/2 to 3/2 by hand, the exact result stays a fraction. Converting to 1.5 first and then hoping the float comes back as 3/2 is how people lose the exact answer this page is meant to keep.
Improper fractions such as 9/4 are allowed and preferred over mixed numbers. The simplified row may stay improper (9/4 → 9/4) or become an integer (8/4 → 2). This page does not rewrite 9/4 as 2 1/4, because that mixed form is a presentation choice, not a different value. If a teacher wants mixed numbers, convert the simplified improper fraction by hand after you trust the exact result.
To talk about the same two numbers as a ratio, use the Ratio Calculator. To compute only gcd or lcm of the integers you already have, use the GCD & LCM Calculator. Those pages do not add 1/2 and 1/3.
Yes. Numerators and denominators are integers. The decimal line is a separate, rounded view of the simplified fraction.
That input is rejected. A fraction with denominator 0 is not a number.
0/5 is zero. Division by that fraction is rejected.
No. Enter improper fractions such as 3/2. Mixed-number parsing is a different interface.
