FractionReference

Multiply fractions

Straight across the top, straight across the bottom, reduced at the end.

Try: — fractions, mixed numbers and decimals all work, negatives included.

Common questions

How do I multiply fractions?
Multiply the numerators, multiply the denominators, then reduce: 2/3 × 3/4 = 6/12 = 1/2. No common denominator needed.
Why does multiplying by a fraction make things smaller?
Multiplying by a number less than 1 takes that share of what you had: 3/4 × 1/2 is half of three quarters, which is 3/8. Multiplying by a fraction greater than 1 grows it the same way.
How do I multiply a fraction by a whole number?
A whole number is a fraction over 1: 5 × 3/8 = 5/1 × 3/8 = 15/8 = 1 7/8.
Where this comes from. Exact rational arithmetic on the values shown — fractions are pairs of integers until display, and inch–metric conversion uses 25.4 mm to the inch, exact by definition since 1959. See the full methodology.