Basis weight comparison
A. Ream weight and M weight formulas
To calculate the ream weight (1 ream = 500 sheets) of any sheet size, multiply the sheet length by the sheet width by the basis weight and divide by the number of square inches associated with the basis weight.
Example:
20" x 30" basis x 80lb cover
__________________________= 92.3076
520 square inches
To calculate the M weight (1,000 sheets) for sheets smaller than 24x36, adjust the ream weight to the nearest half-pound and multiply by 2. For sheets 24x36 and larger, adjust the ream weight to the nearest pound and multiply by 2.
B. Sheet area of Standard Basis Size
25 x 38 = 950 - Book 17 x 22 = 374 - Bond, ledger, writing, vellum
20 x 26 = 520 - Cover 22½ x 28½ = 641 - Bristol
25½ x 30½ = 778 - Index 24 x 36 = 864 - Kraft, tag, newsprint
C. Basis weight comparisons
Based on ream weights
| |
|
17 x 22 |
25 x 38 |
20 x 26 |
22½ x 28½ |
25½ x 30½ |
24 x 36 |
Grams/
SQ Meter |
|
| |
Bond |
20 |
50 |
27 |
34 |
41 |
45 |
74 |
|
| |
Bond |
20
24
28 |
50
60
70 |
27
32
38 |
34
40
47 |
41
49
57 |
45
55
64 |
74
89
104 |
|
| |
Offset and Opaque |
30
32
39
41
43
50 |
75
80
100
105
108
128 |
41
43
55
57
59
70 |
51
54
67
71
73
86 |
61
66
82
86
88
105 |
68
73
91
95
98
116 |
111
118
148
155
160
189 |
|
| |
Cover |
47
58 |
119
146 |
65
80 |
80
98 |
69
118 |
108
133 |
176
216 |
|
| |
Vellum Bristol
Cover |
33
39
46 |
84
100
118 |
46
54
65 |
57
67
80 |
69
81
98 |
77
90
109 |
125
147
175 |
|
| |
Index |
43
53
67 |
110
135
170 |
60
74
93 |
74
91
115 |
90
110
40 |
100
122
156 |
163
199
253 |
|
| |
Tag |
43
54
65 |
110
137
165 |
60
75
90 |
74
93
111 |
90
113
135 |
100
125
150 |
163
203
244 |
|