Paper - The Graphic Design: Reference and Specification - page 66

g r a m m a g e
Outside of North America, the weight of paper is measured in grams per square meter
(gsm). The grammage system measures the weights of all papers without taking into
consideration their size or grade. This system standardizes a ream at 500 sheets and
defines a sheet as 1 square meter (A size). The term grammage is used to define the
basis weight of all grades of paper measured in grams per square meter.

The following list gives some basis weight and grammage equivalents. Because North
American basis weights are based on different basic sizes, the progression of weight
conversion may not seem to be as logical as the basis weight comparisons on the
opposite page.

Paper grade Equivalent to Paper grade Equivalent to

16# bond 59 gsm 60# cover 162 gsm

24# bond 89 gsm 65# cover 176 gsm

80# cover 216 gsm

67# bristol 148 gsm 100# cover 270 gsm

80# bristol 178 gsm 120# cover 325 gsm

100# bristol 219 gsm

120# bristol 263 gsm 90# index 163 gsm

140# bristol 307 gsm 110# index 199 gsm

140# index 253 gsm

30# text 44 gsm 170# index 308 gsm

40# text 59 gsm

45# text 67 gsm

60# text 89 gsm

70# text 104 gsm

80# text 118 gsm

100# text 148 gsm

Converting Basis Weight to Grammage
To convert the basis weight of a paper to its grammage, look up the sheet size in the
left-hand column of the chart below. “lb." means pounds (basis weight).

Size Basis weight to grammage Grammage to basis weight

17" × 22" (432 × 559 mm) 3.760 × lb. = gsm 0.266 × gsm = lb.

20" × 26" (508 × 660 mm) 2.704 × lb. = gsm 0.370 × gsm = lb.

22 " × 28 " (559 × 711 mm) 2.282 × lb. = gsm 0.438 × gsm = lb.

22 1 ⁄ 2 " × 28 1 ⁄ 2 " (572 × 724 mm) 2.195 × lb. = gsm 0.456 × gsm = lb.

24" × 36" (610 × 914 mm) 1.627 × lb. = gsm 0.614 × gsm = lb.

25" × 38" (635 × 965 mm) 1.48 × lb. = gsm 0.675 × gsm = lb.