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Conversionsoffice

Paper Size Converter

Paper sizes in millimetres, inches and pixels. The A series has an aspect ratio of the square root of two, which is why folding a sheet in half gives the next size down with the same proportions.

Also called: a4 size in pixels, paper size chart.

Dimensions
210 by 297 mm

210 by 297 mm, or 8.27 by 11.69 inches. At 300 dpi that is 2,480 by 3,508 pixels. The area is 0.06 square metres. The A series has an aspect ratio of root two, so halving the long side gives the next size down with the same proportions.

In inches
8.27 by 11.69 inches
Width
210
Height
297
Pixels wide
2,480
Pixels tall
3,508
Area in square metres
0.06
Aspect ratio
1.41
On the A series
The A series has an aspect ratio of root two, so halving the long side gives the next size down with the same proportions.
How this is calculated
Method and background

How this is calculated

A0 is defined as one square metre of area with sides in the ratio of root two to one. Halving the long side gives A1, which has the same ratio, and so on down. That property is why scaling A4 artwork to A3 needs no cropping, and why photocopier enlargement factors are clean numbers: A4 to A3 is exactly root two, about 141 percent. US sizes have no such relationship, which is why letter to legal is not a proportional scale.

the A series keeps its proportions when halved, which is the property the whole system is built on
h, w
Height and width

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

A4 at print resolution

Paper size
A4
Resolution for pixel dimensions
300

Dimensions210 by 297 mm

210/25.4 x 300

Open this example

A0 is one square metre

Paper size
A0
Resolution for pixel dimensions
300

Dimensions841 by 1189 mm

boundary: the definition of the series, rounded to whole millimetres

Open this example

Method and limits

What it assumes

  • ISO 216 dimensions, rounded to the nearest millimetre as the standard specifies.

What it deliberately does not model

  • Print bleed and trim margins are separate and not included here.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

Why is enlarging A4 to A3 exactly 141 percent?
Because the ratio between consecutive A sizes is the square root of two, which is 1.414. That is the same property that keeps the proportions constant.
Why does US Letter not scale like A4?
US sizes are not built on a constant ratio. Letter is 8.5 by 11 inches and legal 8.5 by 14, so scaling one to the other changes the proportions.