How to use the multiplying fractions calculator
Type the fractions to multiply (up to 5 with How many; tick Mixed numbers for values like 1 1/2) and press Calculate. The working shows cancelling, multiplying and simplifying.
How to multiply fractions
Multiply the numerators together and the denominators together – no common denominator is needed:
\frac{a}{b} \times \frac{c}{d} = \frac{a \times c}{b \times d} \qquad \frac{2}{3} \times \frac{4}{5} = \frac{2 \times 4}{3 \times 5} = \frac{8}{15}Cancel first to keep numbers small
If a numerator and a denominator share a factor, divide both by it before multiplying. The answer comes out already simplified:
\frac{2}{3} \times \frac{9}{10} = \frac{\cancel{2}^{\,1}}{\cancel{3}_{\,1}} \times \frac{\cancel{9}^{\,3}}{\cancel{10}_{\,5}} = \frac{1 \times 3}{1 \times 5} = \frac{3}{5}Mixed numbers and whole numbers
- Change mixed numbers to improper fractions first: 1 1/2 × 2 2/3 = 3/2 × 8/3 = 4.
- Write a whole number over 1: 3 × 2/5 = 3/1 × 2/5 = 6/5 = 1 1/5.
- “Of” means multiply: 2/3 of 12 = 2/3 × 12 = 8.
Do not multiply the whole parts and fraction parts of mixed numbers separately – 1 1/2 × 2 1/2 is 3 3/4, not 2 1/4.
Worked examples
Frequently asked questions
How do you multiply fractions?
Multiply the numerators, multiply the denominators, then simplify: 2/3 × 4/5 = 8/15.
Do you need a common denominator to multiply fractions?
No. A common denominator is only needed for adding and subtracting.
How do you multiply a fraction by a whole number?
Write the whole number over 1 and multiply: 3 × 2/5 = 6/5 = 1 1/5.
What is cross-cancelling?
Dividing a numerator and a denominator (from either fraction) by a common factor before multiplying, so the numbers stay small.
How do you multiply mixed numbers?
Change them to improper fractions, multiply, and change the answer back: 1 1/2 × 2 2/3 = 3/2 × 8/3 = 4.