In an effort to help eliminate the "Paper Weight" confusion problem, we have compiled the comprehensive table listed below. Now you can compare various types of paper and their "Equivalent Weights."
The basis weight of a paper is the designated fixed weight of 500 sheets, measured in pounds, in that paper's basic sheet size. It is important to note that the "basic sheet size" is not the same for all types of paper.
Caliper refers to the thickness of a sheet of paper expressed in thousandth of an inch. This measurement is taken with a micro meter. Normally, paper caliper should not have more than a + or - 5% variance within a sheet. Generally, the relation between caliper and basis weight – the greater the caliper (the thicker the paper), the greater the paper weight.
While different paper types have different basic sizes, papers can still be compared by using equivalent weight.
Basis Weight ("Category") Table
Paper Weights Table