Standard Paper Sizes

By: Dana Byerwalter, Editor, AllFreePaperCrafts

Have you ever wondered how paper size is measured and why? Why do certain paper sizes have that little "a" in front of them, while other sizes are measured in a different way? Consult this guide to Standard Paper Sizes. Here you will learn what the International Organization for Standardization deems standard size paper, and you will also learn of other standard sizes. For a quick go-to guide for paper sizes, this is a wonderful reference to consult.

Standard Paper Sizes

The International Organization for Standardization has compiled the 216 series of paper dimensions. The dimensions are measured at a ratio of 1:(sq rt of 2). These unique dimensions mean that each time a sheet of this paper is folded in half, the aspect ratio remains the same. The chart above does an excellent job of showing this. Each size in the A series is measured by halves: begin with A0. Half of A0 is the A1 size. Half of the A1 size is A2, and so on. This is true of the B series and C series as well, but each series follows different dimensions. The C series, for example, is how envelopes for the A series are measured.

ISO 216: A Series

	A Series
size	mm	inches
0	841 x 1189	33.11 x 46.81
1	594 x 841	23.38 x 33.11
2	420 x 594	16.53 x 23.38
3	297 x 420	11.69 x 16.53
4	210 x 297	8.26 x 11.69
5	148 x 210	5.82 x 8.26
6	105 x 148	4.13 x 5.82
7	74 x 105	2.91 x 4.13
8	52 x 74	2.04 x 2.91
9	37 x 52	1.5 x 2.04
10	26 x 37	1.0 x 1.5

ISO 216: B Series

	B Series
Size	mm	inches
0	1000 x 1414	39.4 x 55.7
1	707 x 1000	27.8 x 39.4
2	500 x 707	19.7 x 27. 8
3	353 x 500	13.9 x 19.7
4	250 x 353	9.8 x 13.9
5	176 x 250	6.9 x 9.8
6	125 x 176	4.9 x 6.9
7	88 x 125	3.5 x 4.9
8	62 x 88	2.4 x 3.5
9	44 x 62	1.7 x 2.4
10	31 x 44	1.2 x 2.7

ISO 216: C Series (envelopes)

	C Series
Size	mm	inches
0	917 x 1297	36.1 x 51.1
1	648 x 917	25.5 x 36.1
2	458 x 648	18.0 x 25.5
3	324 x 458	12.8 x 18.0
4	229 x 324	9.0 x 12.8
5	162 x 229	6.4 x 9.0
6	114 x 162	4.5 x 6.4
7	81 x 114	3.2 x 4.5
8	57 x 81	2.2 x 3.2
9	40 x 57	1.6 x 2.2
10	28 x 40	1.1 x 1.6

Other Standard Paper Sizes

Name	mm	inches
Letter (printer)	215.9 x 279.4	8.5 x 11.0
Legal	215.9 x 355.6	8.5 x 14.0
Junior Legal	127 x 203	5.0 x 8.0
Ledger/Tabloid	279 x 432	11.0 x 17.0