12/18 expressed as a percentage is 66.67%. This value tells you how much of a whole the fraction represents when it is turned into a percent.
If you simplify the fraction, 12/18 reduces to 2/3. Both forms describe the same part of a whole, just in different ways—one as a fraction, the other as a percent.
In everyday situations, you might see 66.67% used to show a two‑thirds share, such as two out of three students passing a test or two‑thirds of a pizza being eaten.
Remember that the percentage is rounded to two decimal places, so it’s a close approximation of the exact value.