A4 dimensions are 210 × 297 mm, 21 × 29.7 cm, or 8.27 × 11.69 inches. The ISO 216 standard sets this size. You can verify it on the ISO 216 standard page.

In the US, the default sheet is Letter, not A4. That causes cut-off text, odd margins, and wrong frame sizes. This guide gives exact numbers and quick fixes.

A4 Paper Size in Inches, CM and MM

Here is the A4 paper size in every common unit:

Unit	Width × Height
Millimeters (mm)	210 × 297
Centimeters (cm)	21 × 29.7
Inches (in)	8.27 × 11.69
Meters (m)	0.21 × 0.297
Feet (ft)	0.69 × 0.97
Points (pt)	595 × 842
Picas (pc)	49.6 × 70.2

You may see A4 size in inches written three ways. The exact value is 8.268 × 11.693. Most sites round it to 8.27 × 11.69. Some print guides show 8¼ × 11¾. All three describe the same sheet.

The area of one A4 sheet is about 623.7 cm² (0.0624 m²). Most word processors set a default margin of about 1 inch (25 mm) on each side.

A4 Size in Pixels

Pixels depend on DPI (dots per inch). Pick the DPI that fits your goal:

DPI	A4 size in pixels	Best use
72	595 × 842	Screen and web
96	794 × 1123	Windows display
150	1240 × 1754	Draft print
300	2480 × 3508	High-quality print

For a print-ready file, use 300 DPI and CMYK color. Export it as a PDF to keep the layout fixed.

Understanding dimensions is useful beyond paper and printing, especially when planning the space needed for recreational equipment. If you’re setting up a game room, knowing the standard pool table sizes can help you choose the right table and ensure enough room for comfortable play.

A4 vs US Letter Size (8.5 x 11)

A4 is narrower and taller than US Letter. The gap looks small, but it shifts layouts.

A4 Paper

• Size: 8.27 × 11.69 in (210 × 297 mm)
• Used in most countries, including the UK and across Europe and Asia

US Letter Paper

• Size: 8.5 × 11 in (215.9 × 279.4 mm)
• Used in the US, Canada, and parts of Latin America

A4 is about 0.23 in narrower and 0.69 in taller than Letter. Legal paper is even longer, at 8.5 × 14 in.

What happens when you print A4 on Letter paper? The page is too tall by 0.69 in. Choose Fit to Page or Shrink to Fit in the print dialog. This scales the file to about 94%. Without it, the bottom lines may be cut off.

Sharing files across borders? Set side margins wide enough for both sizes. Keep key text inside a 7.5 × 10.5 in area. It then prints cleanly on A4 and Letter.

A-Series Sizes, Aspect Ratio and Uses

The A series starts at A0, which has an area of one square meter. Cut a sheet in half and you get the next size. That is why the “4” in A4 means four cuts from A0.

Size	mm	Inches
A0	841 × 1189	33.11 × 46.81
A1	594 × 841	23.39 × 33.11
A2	420 × 594	16.54 × 23.39
A3	297 × 420	11.69 × 16.54
A4	210 × 297	8.27 × 11.69
A5	148 × 210	5.83 × 8.27
A6	105 × 148	4.13 × 5.83

Every A size shares one aspect ratio: 1:√2, or about 1:1.414. This is why scaling between sizes keeps the layout intact. The math behind it is explained in the ISO 216 overview.

Compare the ratios:

• A4: 1.414
• US Letter: 1.294
• 16:9 screen: 1.778

Common A4 uses:

• Letterhead, forms, and reports
• Resumes and job applications for international roles
• Flyers, brochures, and booklets (fold A4 once for A5, twice for A6)
• Visa, study abroad, and school documents
• Print-on-demand orders shipped from abroad

Envelope fit: A flat A4 sheet fits a C4 envelope. Fold it once for C5. Fold it in three for DL.

Photos: Two 4 × 6 in prints fit side by side on one A4 sheet. For the best result, use photo paper and set the printer to A4.

FAQs About A4 Dimensions

What is the dimension of an A4?

A4 measures 210 × 297 mm. That equals 21 × 29.7 cm and 8.27 × 11.69 inches. In pixels, it is 2480 × 3508 at 300 DPI.

Is A4 the same as 8.5 x11 paper?

No. The 8.5 × 11 in sheet is US Letter. A4 is narrower at 8.27 in wide and taller at 11.69 in.

Is A4 16:9 aspect ratio?

No. A4 has a ratio of about 1:1.414. A 16:9 frame is about 1:1.778, which is much wider.

Is A4 size 8×12?

No. An 8 × 12 in sheet equals about 203 × 305 mm. A4 is wider at 8.27 in and shorter at 11.69 in.

Is 8×12 inch A3?

No. A3 is 11.69 × 16.54 in (297 × 420 mm). An 8 × 12 sheet is much smaller. A3 is twice the area of A4.

Will A4 fit in 8×12?

Not as is. A4 is 0.27 in too wide for an 8 in frame. The height fits. Scale the file to about 97% or trim the sheet, and it will fit.

Conclusion

A4 dimensions are 8.27 × 11.69 inches, 21 × 29.7 cm, and 210 × 297 mm. It is not the same as US Letter, 8×12, or A3. Before you print, check the paper size setting. Use Fit to Page when switching between A4 and Letter.