Fraction Calculator

How to use

1. 1Pick an operation: Add, Subtract, Multiply, or Divide. The expression label updates to match.
2. 2Type the first fraction into A and the second into B. Use 3/4, 1 2/3, 5, or 1.25; negative values use a leading minus sign.
3. 3Read the answer at the top right and the simplified fraction, mixed number, and decimal value rows below it.
4. 4Open the Step-by-step working panel to see exactly how the common denominator, numerator math, and final simplification were done.
5. 5Click any Copy button (full result, fraction, mixed, or decimal) to grab the value, or use Swap A and B and Clear inputs to reset and try a new pair.

About this tool

Fraction Calculator adds, subtracts, multiplies, and divides any two fractions and reports the result in three forms: a simplified fraction in lowest terms, a mixed number when the magnitude is at least one, and a decimal value. Inputs are flexible, so you can mix and match whole numbers like 3 or -7, improper fractions like 5/3, mixed numbers like 1 2/3, and decimals like 1.25 in the same expression. Each input is parsed into an exact (numerator, denominator) pair using BigInt, so values stay precise even when intermediate steps grow into the millions: 999/1000 + 1/1000 lands exactly on 1, not 0.9999999... like a floating-point answer would. Addition and subtraction find a common denominator, combine the numerators, and divide by the greatest common divisor to put the result in lowest terms. Multiplication multiplies tops and bottoms and simplifies. Division flips the second fraction (the reciprocal) and multiplies. Every operation is shown in a step-by-step working list that reads like a math homework explanation, so the tool is just as useful for checking why an answer is what it is as for getting the answer itself. The decimal display also reports repeating decimals exactly: 1/3 is shown as 0.(3), 1/7 as 0.(142857), and 5/12 as 0.41(6), with parentheses marking the exact repetend instead of a rounded approximation. Quick-pick presets cover the most common worksheet questions (1/2 + 1/3, 3/4 - 1/6, 2/5 x 5/8, 7/8 / 1/4, 1 1/2 + 2 3/4, 0.75 + 1/8) so you can see how the tool behaves in one click. Useful for elementary, middle, and high school math homework, fraction word problems, kitchen recipes that scale up or down, woodworking and machining cuts in imperial fractions, sewing patterns, and any time you need exact fraction arithmetic without reaching for a desk calculator that only speaks decimals. Everything runs locally in your browser, so the values you punch in for assignments, exam prep, or shop drawings never leave your device.

Free to use. Works in your browser. No signup, no login.