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Multiply fractions

Enter two fractions and see the product simplified, as a mixed number and as a decimal, with the working shown.

For example 3/4, 1 1/2, −2 or 0.25.

Fill in the fields; the answer appears here straight away.

How it works

  1. Enter the values

    Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.

  2. Instant answer

    The answer appears as you type, with the most important intermediate values.

  3. See the working

    Under "How it's worked out" you see the steps, handy for checking your own calculation.

How to multiply fractions

Multiplying fractions is the easiest operation: multiply the numerators and multiply the denominators. 3/4 × 8/9 = (3 × 8) / (4 × 9) = 24/36, which simplifies to 2/3. You don't need a common denominator.

Mixed numbers are turned into improper fractions first: 1 1/2 × 2/3 = 3/2 × 2/3 = 6/6 = 1.

Input

Fractions, mixed numbers, whole numbers and decimals, positive or negative. The answer is exact. To divide, use divide fractions.

Cancelling before you multiply

Take 4/9 × 3/8. Multiplying straight through gives 12/72, which simplifies to 1/6. It is easier to cancel first: 4 and 8 share a factor 4, and 3 and 9 share a factor 3. That leaves 1/3 × 1/2 = 1/6. The calculator multiplies first and then reduces, which gives the same result.

"Of" means multiply

Two thirds of 24 is 2/3 × 24 = 48/3 = 16. A recipe for 4 people that needs 3/4 cup of flour needs 1 1/2 × 3/4 = 9/8 = 1 1/8 cups when you cook for 6. Fractions of an amount, and scaled recipes, are the most common uses.

Percentages are fractions too

25% is 1/4 and 12.5% is 1/8, so finding 12.5% of something is the same as multiplying by 1/8. To go the other way, use the percentage calculator. To simplify a result by hand, the GCD calculator helps.

Frequently asked questions

Why don't I need a common denominator to multiply fractions?

Because multiplying means taking a part of a part. Multiplying the numerators and the denominators directly gives the right size of piece: 1/2 × 1/3 = 1/6.

How do I multiply a fraction by a whole number?

Treat the whole number as a fraction over 1. 5 × 2/3 = 5/1 × 2/3 = 10/3, which is 3 1/3.

How do I multiply mixed numbers?

Turn them into improper fractions first. 1 1/2 × 2 2/3 is 3/2 × 8/3 = 24/6 = 4.

Can multiplying make a number smaller?

Yes, when you multiply by a fraction smaller than 1. Half of 24 is 1/2 × 24 = 12, and 2/3 of 24 is 16.