What Size Is A4 in Inches?

A4 paper is 8.27 × 11.69 inches (210 × 297 mm). It is the standard paper size used in most countries outside North America, defined by the ISO 216 international standard.

A4 Conversion Table

UnitWidthHeight
Millimeters210297
Centimeters21.029.7
Inches8.2711.69
Pixels @ 300 DPI24803508
Pixels @ 150 DPI12401754

A4 vs US Letter

PropertyA4US Letter
Inches8.27 × 11.698.5 × 11
Millimeters210 × 297216 × 279
Area (sq in)96.6793.50
Aspect Ratio1:√2 (≈1:1.414)1:1.294

US Letter is slightly wider (by 6mm) and shorter (by 18mm) than A4. This difference causes formatting issues when printing documents designed for one size on the other.

Common Uses for A4

  • Office documents (international standard)
  • Magazines and catalogs
  • Business letters
  • Academic papers
  • Most home and office printers support A4

A4 is part of the ISO A series where each size is half the next larger size:

  • A3 (twice A4): 11.69 × 16.54 inches
  • A5 (half of A4): 5.83 × 8.27 inches
  • C4 envelope fits A4 unfolded

For the complete A series table, see A Series Paper Sizes. For the A4 vs Letter comparison, see Letter vs A4.

Frequently Asked Questions

What is A4 paper size in inches?

A4 paper measures 8.27 x 11.69 inches (210 x 297 millimeters). It is the international standard paper size defined by ISO 216.

Is A4 the same as US Letter?

No. A4 (8.27 x 11.69 inches) is slightly narrower and taller than US Letter (8.5 x 11 inches). A4 is 0.23 inches narrower and 0.69 inches taller than Letter.

How many pixels is A4 at 300 DPI?

A4 at 300 DPI is 2480 x 3508 pixels. At 150 DPI, it is 1240 x 1754 pixels.