Paper Sizes

The ISO 'A' Series
The ISO 'A' series of sheet sizes is based on a constant width to length ratio of 1:2.

The A0 size is defined as having an area of one square meter. This allows paper weights to be expressed in grams per square meter.
Each smaller sheet size is exactly half the area of the previous size. ie. If you cut an A0 sheet in half you get two A1 sheets; If you cut an A1 sheet in half you get two A2 sheets; and so on ...

This relationship of 1:2 is particularly important for reduction onto microfilm, or reduction and enlargement on photocopiers. All metric equipment including microfilm cameras, microfilm printers, photocopiers, and even drawing pen sizes, are designed around this ratio. This makes the process of archiving drawings, resizing, and modifying drawings easy.
Dimensions of Regular Sheets
A0 841 mm x 1189 mm
A1 594 mm x  841 mm
A2 420 mm x  594 mm
A3 297 mm x  420 mm
A4 210 mm x  297 mm
A5 149 mm x  210 mm
Oversize Sheets
Oversize sheets are used when it is desirable to give extra protection to the drawing sheets by providing a binding or trimming margin.
Dimensions of Oversize Sheets
RA0 860 mm x 1220 mm
RA1 610 mm x  860 mm
RA2 430 mm x  610 mm
RA3 305 mm x  430 mm
RA4 215 mm x  305 mm
RA5 153 mm x  215 mm
The standard widths for rolls is 860 mm and 610 mm. The length of the drawing sheet can be cut as required to suit each individual drawing.
The ISO 'B' Series
The ISO 'B' series is defined to satisfy the requirements of drawing offices when the differences between the 'A' series sizes is too great. In practice they are not commonly used.
Dimensions of Regular Sheets
B01000 mm x 1414 mm
B1 707 mm x 1000 mm
B2 500 mm x  707 mm
B3 354 mm x  500 mm
B4 250 mm x  354 mm
B5 177 mm x  250 mm
Non-Metric Paper Sizes
For reference purposes the following table lists non-metric paper sizes still in use in some parts of the world.
DesignationDimensions (mm)Dimensions (in)
US Engineering:
ANSI A 215.9 mm x  279.4 mm8.5" x 11"
ANSI B 279.4 mm x  431.8 mm11" x 17"
ANSI C 431.8 mm x  558.8 mm17" x 22"
ANSI D 558.8 mm x  863.6 mm22" x 34"
ANSI E 863.6 mm x 1117.6 mm34" x 44"
US Architectural:
ARCH A 228.6 mm x  304.8 mm 9" X 12"
ARCH B 304.8 mm x  457.2 mm12" X 18"
ARCH C 457.2 mm x  609.6 mm18" X 24"
ARCH D 609.6 mm x  914.4 mm24" X 36"
ARCH E 914.4 mm x 1219.2 mm36" X 48"
Letter 215.9 mm x  279.4 mm8.5" x 11"
Legal 215.9 mm x  355.6 mm8.5" x 14"
US Government 203.2 mm x  279.4 mm 8" x 11"
Statement 139.7 mm x  215.9 mm5.5" x 8.5"
Executive 184.2 mm x  266.7 mm7.25" x 10.5"
Folio 215.9 mm x  330.2 mm8.5" x 13"
Quarto 215.0 mm x  275.0 mm
Tabloid 279.4 mm x  431.8 mm11" x 17"
Ledger 279.4 mm x  431.8 mm11" x 17"

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