per cent | percentage

The use of percentages is a way of expressing ratios in terms of whole numbers. A ratio or fraction is converted to a percentage by multiplying by 100 and appending a "percentage sign" %. For example, if an investment grows from P = 13. to A = 22.5, then A is 22.5/13. = 1.7308 times as much as P, i.e., 173.08% of P. So it is also true that the investment has grown by 173.08% - 100% = 73.08%. A change of a certain percent n is sometimes said to be a change of percentage points.

basis point | percentage error | percentage point | permil