What is A4 in millimeters, centimeters and inches?

A4 is nominally 210 × 297 mm, or 21 × 29.7 cm and approximately 8.2677 × 11.6929 inches. Landscape swaps the sides. Letter is 8.5 × 11 inches (215.9 × 279.4 mm), so A4 is 5.9 mm narrower and 17.6 mm taller. A3 is 297 × 420 mm and A5 is 148 × 210 mm. Select any of them for the dimensions, area and relative outlines.

Does changing A4 to Letter crop or reflow a document?

Neither sheet fits fully inside the other at the same orientation. Changing the document page size can reflow text, depending on the application and layout. A PDF printed with fit-to-page is scaled; it does not reflow its text. Actual-size printing can clip content outside the printable area. This lookup neither edits a document nor sets a printer driver.

How many pixels is a paper sheet?

There is no fixed pixel size without a resolution. Multiply each dimension in inches by pixels per inch and round to a whole pixel. A4 at 300 ppi is 2480 × 3508 px; at 150 ppi it is 1240 × 1754 and at 72 ppi it is 595 × 842. Letter is 2550 × 3300 px at 300 ppi. Enter another PPI / DPI above. Here DPI is the familiar input label for raster sizing; a printer’s dots per inch and an image’s pixels per inch describe different things. A 72 ppi setting does not determine how large an image looks on every screen.

Are ISO B5 and Japanese JIS B5 the same size?

No. ISO B5 is 176 × 250 mm; JIS B5 is 182 × 257 mm. JIS B4 is 257 × 364 mm, whereas ISO B4 is 250 × 353 mm. The Japanese A series uses the same nominal dimensions as ISO A. Use the separate JIS entries and the JIS B5 comparison page before choosing a notebook, print canvas or printer setting.

What is the difference between ARCH and ANSI drawing sizes?

ARCH D is 24 × 36 inches (609.6 × 914.4 mm); ANSI D is 22 × 34 inches (558.8 × 863.6 mm). ARCH C is 18 × 24 inches; ANSI C is 17 × 22. They are separate drawing-sheet series, even when their letters match. ARCH E1 is 30 × 42 and ARCH E is 36 × 48 inches. Select the series in the reference chart to see the full listed set. This is a sheet-dimension lookup, not an assessment of drawings or construction.

What is Legal paper, and is 8.5 × 13 the same?

US Legal is 8.5 × 14 inches, or 215.9 × 355.6 mm and 21.59 × 35.56 cm. Letter has the same width and is three inches shorter. An 8.5 × 13 sheet is 215.9 × 330.2 mm and has its own Folio / 8.5 × 13 entry. Folio, Long Bond, Government Legal and regional Legal names vary by supplier and driver. Mexico Legal, for example, is listed by Brother as 8.5 × 13.38 inches, while other drivers use approximately 340 mm. Enter the dimensions your supplier specifies as a custom sheet; do not assume every Legal label means US Legal.

Which envelope takes A4, A6 or Letter?

C4 is nominally 229 × 324 mm for A4 unfolded; C5 is 162 × 229 mm for A4 folded once; DL is 110 × 220 mm for A4 folded in thirds. C6 is 114 × 162 mm for A6 flat. No. 10 is 4.125 × 9.5 inches for Letter folded in thirds. A common 9 × 12 inch catalog envelope accommodates Letter unfolded. Listed outer dimensions do not guarantee usable internal clearance, especially for thick stacks. US A2 and A7 invitation envelopes are separate names from ISO A2 and A7 paper.

How do I copy a paper size chart?

Choose Chart series, orientation and PPI / DPI. Copy chart puts a tab-separated reference on your clipboard; Download chart TSV prepares the same table as a file for a spreadsheet or document. The chart contains nominal millimeters, centimeters, inches, chosen-resolution pixels and uses. It is a dimension reference, not a full-size printable paper template.

Are the sizes and aspect ratios exact?

The lookup uses nominal trimmed dimensions. ISO A and B use the ideal square-root-of-two proportion; their whole-millimeter dimensions approximate it. ISO 216 permits trimming tolerances, so an actual sheet may differ from the listed numbers. The traditional C envelope series was specified separately by ISO 269, now withdrawn, and remains a common convention. Inch-defined US and ARCH dimensions are converted using 25.4 mm per inch. Photo centimeter labels are approximate trade equivalents. Bleed, printer margins and borderless support are separate from sheet dimensions.

Can I print several A6 PDF pages on A4 or Letter?

Use the linked PDF N-up and Booklet Imposition tool for an existing PDF. Choose N-up, A4 or Letter output, portrait, two columns and two rows, then set margins and gutter for your printer. Four A6 pages nearly fill A4 at their nominal dimensions; Letter requires reduction to fit a 2 × 2 layout. The imposed PDF preserves selectable content; print the exported sheet at actual size. This lookup does not itself arrange or print a document.

Paper Sizes

Look up listed paper sizes in millimeters, centimeters, inches and pixels, and compare two sheets to scale. Choose portrait or landscape and enter the PPI / DPI for your raster canvas; the 72, 150 and 300 ppi readings remain available. ISO A and B, the traditional C envelope series, Japanese JIS B, North American Letter, Legal, ANSI and ARCH drawing sheets, photo prints, business cards and common envelopes have separate entries. Custom dimensions let you compare an unlisted or square sheet against a listed one. Every size tells you whether it fits inside the other nominal outline; this is not a printer compatibility or stock-measurement check.

A4 · 210 × 297 mm
Letter · 215.9 × 279.4 mm

A4210 × 297 mm8.27 × 11.69 in · 2480 × 3508 px at 300 ppi

Size

Compare with

Units

PPI / DPI

Custom sides are normalized to short × long in portrait; landscape turns both sheets. PPI sets the raster canvas size; it does not set screen size or guarantee print quality.

A4 is 5.9 mm narrower and 17.6 mm taller than Letter.

Millimeters
210 × 297 mm
Centimeters
21 × 29.7 cm
Inches
8.27 × 11.69 in
Pixels at 72 ppi
595 × 842 px
Pixels at 150 ppi
1240 × 1754 px
Pixels at 300 ppi
2480 × 3508 px
Pixels at chosen 300 ppi
2480 × 3508 px
Aspect ratio
1 : 1.414
Area
623.7 cm² · 96.67 in²
Against Letter
Neither fits inside the other: Letter is the wider sheet and A4 is the taller one.

The standard document sheet almost everywhere.
The series uses a nominal 1 to square root of 2 ratio. Whole-millimeter trimmed dimensions approximate that shape.
Two A4 sheets side by side make A3, and folding A4 in half gives A5, allowing for whole-millimeter nominal rounding.
Letter is 5.9 mm wider and 17.6 mm shorter.

Paper size reference chart

Chart series

The international standard. A4 is the everyday document sheet outside North America. Chart dimensions follow the chosen orientation and resolution.

ISO A series · portrait · 300 ppi
Millimeters	Inches	Pixels at 300 ppi	Used for
841 × 1189 mm	33.11 × 46.81 in	9933 × 14043 px	The base sheet the whole A series is halved from.
594 × 841 mm	23.39 × 33.11 in	7016 × 9933 px	Large posters and flip charts.
420 × 594 mm	16.54 × 23.39 in	4961 × 7016 px	Medium posters and technical drawings.
297 × 420 mm	11.69 × 16.54 in	3508 × 4961 px	Charts, spreads and oversized printouts.
210 × 297 mm	8.27 × 11.69 in	2480 × 3508 px	The standard document sheet almost everywhere.
148 × 210 mm	5.83 × 8.27 in	1748 × 2480 px	Notebooks, flyers and folded A4 leaflets.
105 × 148 mm	4.13 × 5.83 in	1240 × 1748 px	Postcards, index cards and small flyers.
74 × 105 mm	2.91 × 4.13 in	874 × 1240 px	Pocket notes and small tickets.
52 × 74 mm	2.05 × 2.91 in	614 × 874 px	Small labels and card-sized cuts.
37 × 52 mm	1.46 × 2.05 in	437 × 614 px	Tiny labels and tags.
26 × 37 mm	1.02 × 1.46 in	307 × 437 px	The smallest A cut, used for stamps and labels.

Compare Japanese JIS B5 with ISO B5 · Compare ARCH with ANSI drawing sheets
For an existing PDF, place four A6 pages on an A4 or Letter sheet with PDF N-up; export there, then print at actual size. To convert arbitrary artwork dimensions, use Pixels to Print Size.

A4 and Letter are not interchangeable. A4 is 5.9 mm narrower and 17.6 mm taller. Changing document page size can reflow content; print-time fit scaling changes its physical size instead. Printer margins, borderless support, bleed and accepted paper depend on the device or print service. Nominal outline fit does not guarantee clearance inside an envelope. These diagrams compare sheets to each other, not to actual screen inches.

Nominal A series and North American dimensions

Portrait dimensions with raster counts at 300 ppi. Inch conversions are displayed rounded; pixel counts use the unrounded dimensions and round only at the whole pixel. The interactive chart above also covers ISO B, C envelopes, JIS B, ARCH, photos and cards.

Size	Millimeters	Inches	Pixels at 300 ppi	Used for
A0	841 × 1189	33.11 × 46.81	9933 × 14043	The base sheet the whole A series is halved from.
A1	594 × 841	23.39 × 33.11	7016 × 9933	Large posters and flip charts.
A2	420 × 594	16.54 × 23.39	4961 × 7016	Medium posters and technical drawings.
A3	297 × 420	11.69 × 16.54	3508 × 4961	Charts, spreads and oversized printouts.
A4	210 × 297	8.27 × 11.69	2480 × 3508	The standard document sheet almost everywhere.
A5	148 × 210	5.83 × 8.27	1748 × 2480	Notebooks, flyers and folded A4 leaflets.
A6	105 × 148	4.13 × 5.83	1240 × 1748	Postcards, index cards and small flyers.
A7	74 × 105	2.91 × 4.13	874 × 1240	Pocket notes and small tickets.
A8	52 × 74	2.05 × 2.91	614 × 874	Small labels and card-sized cuts.
A9	37 × 52	1.46 × 2.05	437 × 614	Tiny labels and tags.
A10	26 × 37	1.02 × 1.46	307 × 437	The smallest A cut, used for stamps and labels.
Folio / 8.5 × 13	215.9 × 330.2	8.5 × 13	2550 × 3900	An 8.5 × 13 inch sheet; regional Folio and Legal names vary, so check the dimensions.
Letter (ANSI A)	215.9 × 279.4	8.5 × 11	2550 × 3300	The default sheet in the US, Canada and Mexico.
Legal	215.9 × 355.6	8.5 × 14	2550 × 4200	US contracts and legal pads, three inches longer.
Tabloid (ANSI B)	279.4 × 431.8	11 × 17	3300 × 5100	US newspapers, spreads and two-up Letter.
Executive	184.15 × 266.7	7.25 × 10.5	2175 × 3150	US letterheads and memos, just under Letter.
Half Letter	139.7 × 215.9	5.5 × 8.5	1650 × 2550	US notepads, planners and half-sheet handouts.
Junior Legal	127 × 203.2	5 × 8	1500 × 2400	Small US legal pads.
Government Letter	203.2 × 266.7	8 × 10.5	2400 × 3150	US school and government notepads.
ANSI C	431.8 × 558.8	17 × 22	5100 × 6600	Engineering drawings, four Letter sheets.
ANSI D	558.8 × 863.6	22 × 34	6600 × 10200	Engineering drawings, eight Letter sheets.
ANSI E	863.6 × 1117.6	34 × 44	10200 × 13200	Engineering drawings, sixteen Letter sheets.

Common questions

What is A4 in millimeters, centimeters and inches?: A4 is nominally 210 × 297 mm, or 21 × 29.7 cm and approximately 8.2677 × 11.6929 inches. Landscape swaps the sides. Letter is 8.5 × 11 inches (215.9 × 279.4 mm), so A4 is 5.9 mm narrower and 17.6 mm taller. A3 is 297 × 420 mm and A5 is 148 × 210 mm. Select any of them for the dimensions, area and relative outlines.
Does changing A4 to Letter crop or reflow a document?: Neither sheet fits fully inside the other at the same orientation. Changing the document page size can reflow text, depending on the application and layout. A PDF printed with fit-to-page is scaled; it does not reflow its text. Actual-size printing can clip content outside the printable area. This lookup neither edits a document nor sets a printer driver.
How many pixels is a paper sheet?: There is no fixed pixel size without a resolution. Multiply each dimension in inches by pixels per inch and round to a whole pixel. A4 at 300 ppi is 2480 × 3508 px; at 150 ppi it is 1240 × 1754 and at 72 ppi it is 595 × 842. Letter is 2550 × 3300 px at 300 ppi. Enter another PPI / DPI above. Here DPI is the familiar input label for raster sizing; a printer’s dots per inch and an image’s pixels per inch describe different things. A 72 ppi setting does not determine how large an image looks on every screen.
Are ISO B5 and Japanese JIS B5 the same size?: No. ISO B5 is 176 × 250 mm; JIS B5 is 182 × 257 mm. JIS B4 is 257 × 364 mm, whereas ISO B4 is 250 × 353 mm. The Japanese A series uses the same nominal dimensions as ISO A. Use the separate JIS entries and the JIS B5 comparison page before choosing a notebook, print canvas or printer setting.
What is the difference between ARCH and ANSI drawing sizes?: ARCH D is 24 × 36 inches (609.6 × 914.4 mm); ANSI D is 22 × 34 inches (558.8 × 863.6 mm). ARCH C is 18 × 24 inches; ANSI C is 17 × 22. They are separate drawing-sheet series, even when their letters match. ARCH E1 is 30 × 42 and ARCH E is 36 × 48 inches. Select the series in the reference chart to see the full listed set. This is a sheet-dimension lookup, not an assessment of drawings or construction.
What is Legal paper, and is 8.5 × 13 the same?: US Legal is 8.5 × 14 inches, or 215.9 × 355.6 mm and 21.59 × 35.56 cm. Letter has the same width and is three inches shorter. An 8.5 × 13 sheet is 215.9 × 330.2 mm and has its own Folio / 8.5 × 13 entry. Folio, Long Bond, Government Legal and regional Legal names vary by supplier and driver. Mexico Legal, for example, is listed by Brother as 8.5 × 13.38 inches, while other drivers use approximately 340 mm. Enter the dimensions your supplier specifies as a custom sheet; do not assume every Legal label means US Legal.
Which envelope takes A4, A6 or Letter?: C4 is nominally 229 × 324 mm for A4 unfolded; C5 is 162 × 229 mm for A4 folded once; DL is 110 × 220 mm for A4 folded in thirds. C6 is 114 × 162 mm for A6 flat. No. 10 is 4.125 × 9.5 inches for Letter folded in thirds. A common 9 × 12 inch catalog envelope accommodates Letter unfolded. Listed outer dimensions do not guarantee usable internal clearance, especially for thick stacks. US A2 and A7 invitation envelopes are separate names from ISO A2 and A7 paper.
How do I copy a paper size chart?: Choose Chart series, orientation and PPI / DPI. Copy chart puts a tab-separated reference on your clipboard; Download chart TSV prepares the same table as a file for a spreadsheet or document. The chart contains nominal millimeters, centimeters, inches, chosen-resolution pixels and uses. It is a dimension reference, not a full-size printable paper template.
Are the sizes and aspect ratios exact?: The lookup uses nominal trimmed dimensions. ISO A and B use the ideal square-root-of-two proportion; their whole-millimeter dimensions approximate it. ISO 216 permits trimming tolerances, so an actual sheet may differ from the listed numbers. The traditional C envelope series was specified separately by ISO 269, now withdrawn, and remains a common convention. Inch-defined US and ARCH dimensions are converted using 25.4 mm per inch. Photo centimeter labels are approximate trade equivalents. Bleed, printer margins and borderless support are separate from sheet dimensions.
Can I print several A6 PDF pages on A4 or Letter?: Use the linked PDF N-up and Booklet Imposition tool for an existing PDF. Choose N-up, A4 or Letter output, portrait, two columns and two rows, then set margins and gutter for your printer. Four A6 pages nearly fill A4 at their nominal dimensions; Letter requires reduction to fit a 2 × 2 layout. The imposed PDF preserves selectable content; print the exported sheet at actual size. This lookup does not itself arrange or print a document.

Listed sizes are nominal trimmed dimensions, not measurements of your stock. Pixels are inches times the chosen PPI, rounded to whole pixels. Printer margins and bleed are separate.