Fraction Calculator

What is the Fraction Calculator?

The Fraction Calculator is a free, instant tool for doing arithmetic with fractions. Choose an operation — add, subtract, multiply, or divide — enter two fractions, and it returns the exact answer reduced to lowest terms, written as a mixed number, and as a decimal, all at once. Most people reach for it when a fraction problem cannot be done cleanly in their head, such as combining 3/4 and 2/3 or splitting 5/8 in half. Instead of guessing, you get the precise result plus the working that produced it.

How to use it

1. Pick the operation you need: plus, minus, times, or divided by.
2. Enter the first fraction by typing its numerator (top) and denominator (bottom). Add a whole-number part if you are working with a mixed number such as 2 1/2.
3. Enter the second fraction the same way.
4. Read the answer, which updates the moment you type. It appears as a simplified fraction, as a mixed number when the value is greater than one, and as a decimal.
5. Open Show the steps to see exactly how the result was reached, then copy the answer and close the tab. There is no Calculate button to wait on.

The method behind it

The math depends on the operation. To add or subtract, both fractions must share a denominator: a/b plus or minus c/d equals (a times d, plus or minus c times b) over (b times d). The two numerators are combined over the common denominator b times d, then the fraction is reduced. To multiply, you go straight across: a/b times c/d equals (a times c) over (b times d). To divide, you multiply by the reciprocal of the second fraction: a/b divided by c/d equals (a times d) over (b times c). Every result is then simplified by dividing the numerator and denominator by their greatest common divisor (GCD), found with the Euclidean algorithm, so the answer always lands in lowest terms.

Worked examples

• Add: 3/4 plus 2/3. Common denominator 12 gives 9/12 plus 8/12 = 17/12, which is the mixed number 1 5/12, or about 1.4167 as a decimal.
• Multiply: 2/5 times 3/4 = 6/20, which reduces to 3/10, or 0.3.
• Divide: 5/8 divided by 1/2 = (5 times 2) over (8 times 1) = 10/8 = 5/4 = 1 1/4 = 1.25.

Common use cases

• Checking homework or learning how fraction operations work step by step.
• Scaling a recipe up or down, such as halving 3/4 cup or tripling 2/3 teaspoon.
• Woodworking, sewing, and DIY measurements where lengths are in fractions of an inch.
• Comparing or combining time, money, or quantities that are expressed as fractions.
• Converting a messy fraction answer into a clean mixed number or decimal.

Why use this one

Many fraction tools only show the final number. This one shows the full step-by-step work — finding the common denominator, combining, and simplifying — so you can follow and trust the result, which makes it genuinely useful for learning, not just answering. It also gives you the result three ways at once (simplest fraction, mixed number, and decimal) and accepts mixed and whole numbers, not only simple fractions. It is instant, needs no sign-up, and runs entirely in your browser, so the numbers you enter are never uploaded or stored.

Frequently asked questions