12/43 as a percentage is 27.91%. This tells you that the fraction is a little more than a quarter of a whole. In everyday terms, if you split something into 43 equal parts, about 27.91 out of every 100 would be taken.
Seeing the number as a percent makes it easier to compare with other values. For example, 1/4 equals 25%, so 12/43 is just a bit higher. It also shows how small the fraction is when you think about a whole set of 100 items.
Whenever you need to describe a part of a total, using the percentage 27.91% can be clearer than the fraction 12/43. It works well in reports, charts, or simple explanations where a quick sense of size is needed.