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Multiplying Fractions Calculator

Type a fraction or a mixed number in each box and press = to multiply them. The product appears in cards below the button, written as a fraction with its decimal value next to it.

What this tool does

Two text boxes hold the fractions you want to multiply. A simple fraction is written with a slash, such as 1/2, and a mixed number is written with a space, such as 2 1/2. Nothing is worked out until you press the = button.

The answer comes back as a fraction, followed by its value as a decimal. A Copy button writes a result and its unit to the clipboard, and Clear resets the form so you can try another pair.

How the answers are written

Some products have a neat decimal and some do not. 1/2 × 1/2 = 1/4 = 0.25 is exact, while 1/2 × 1/3 = 1/6 ≈ 0.166667 only has a rounded decimal, so the fraction is the exact answer there.

Mixed numbers are welcome in either box and can show up in the answer too: 2 1/2 × 1 1/3 = 10/3 = 3 1/3 ≈ 3.333333. A negative fraction works the same way, as in -1/2 × 1/3 = -1/6 ≈ -0.166667, and a zero gives 0 × 1/3 = 0/1 = 0. Flipping one fraction against the other can land on a whole number, as in 3/2 × 2/3 = 1/1 = 1.

The multiplying fractions formula

Fractions are multiplied straight across: numerator times numerator makes the top of the answer, and denominator times denominator makes the bottom. Written in letters, a/b × c/d = (a × c) / (b × d).

A mixed number is multiplied as the single quantity it stands for. The worked example 2 1/2 × 1 1/3 = 10/3 = 3 1/3 ≈ 3.333333 shows that kind of product end to end.