For easy reference, the following is a summary of the principal standard paper sizes and weights and their conversion equivalents using both the imperial and metric systems.

USA/British	Metric
1 inch	2.54cm
1 foot	0.3048m
1 yard	0.9144m

USA size
Letter size	8.5" x 11"
Legal size	8.5" x 14"
Tabloid size	11" x 17"

A5 size	148mm x 210mm (5.83" x 8.27")
A4 size	210mm x 297mm (8.27" x 11.69")
A3 size	297mm x 420mm (11.69" x 16.54")
A2 size	420mm x 594mm (16.54" x 23.39")

USA		International
Coated Stock (both sides gloss)		Gloss Art Paper
lbs book unit	caliper point	gsm unit
53	2.4	79
57	2.8	85
64	3.2	95
71	3.5	105
76	3.9	113
86	4.3	128
95	4.5	140
106	5.1	157
Coated Stock (both sides matte)		Matte Art Paper
lbs book unit	caliper point	gsm unit
53	3.0	79
57	3.3	85
64	3.9	95
71	4.3	105
76	4.5	113
86	6.5	128
95	8.3	140
Uncoated Book Paper		Woodfree Art Paper
lbs book unit	caliper point	gsm unit
41	2.6	60
47	3.4	70
54	3.5	80
68	4.3	100
81	5.1	120
95	5.9	140
122	8.1	180
Gloss Coated Board Cover		Art Board
lbs book unit	caliper point	gsm unit
70	8	190
78	10	210
85	11	230
96	12	260
115	15	310
Cast Coated 1-side board cover		1-side Art Board
lbs book unit	caliper point	gsm unit
82	9	220
93	10	250
100	12	270
111	13	300
122	15	330
Binding Board		Binding Board
Ounces	thickness	gsm unit
20	1.5mm/ .06"	1000
24	2.0mm/ .08"	1200
32	2.5mm/ .10"	1450
40	3.0mm/ .12"	1750
48	3.5mm/ .14"	2150
USA Paper Size		Metric System
type of stock in inches	weight in lbs	gsm unit
book: 25" x 38"	30	44
	40	59
	45	67
	50	74
	60	89
	70	104
	80	118
	90	133
	100	148
	120	178
cover: 20" x 26"	50	135
	60	162
	65	176
	80	216
	90	243
	100	270
	110	297
bond: 17" x 22"	13	49
	16	60
	20	75
	24	90
	28	105
	32	120
	36	135
	40	158
index card: 25.5" x 30.5"	90	163
	110	199
	140	254
	170	308
tag card: 24" x 36"	100	163
	125	203
	150	244
	175	285
	200	325
newsprint: 24" x 36"	32	52
bristol: 22.5" x 28.5"	57	125
	67	147
	80	175
	100	219